Strategic Combat in CoM

[Nelphine]

Death knghts and pikemen are also armor piercing. I think there's one more as well.

Edit: storm giants.

And yeah, pikemen are already the highest potential strategic value in the game, so you'd want to be very careful about any changes to armor piercing.
Although a flat number has a much lower potential than the percentage used right now. So flat number is probably better, but things like storm giants and great wyrms would be hit rather hard.

[Seravy]

Okay, now that it's finally not the middle of the night and I can think properly, let's look at the units.

Chaos Spawn
This has 174 power.

-That's actually stronger than almost every elite level magic weapon normal unit in the game, with a very few exceptions.
-These are extremely easy to kill for the human player in lairs and towers (by ranged and kiting). So having a low rating, to allow the AI to do the same, is good.
-The AI doesn't summon many of these, as it performs poorly in normal combat, unless a human is playing it and can employ tricks to make it reach the enemy units and not get killed by spells and ranged attacks meanwhile. So its rating for AI use is not very relevant.
-The AI likely shouldn't be scared of this unit on the overland map - the chance of it being able to kill it with spells and ranged attacks is fairly high, at least better if the AI ambushes the monster than if the human can pick a target to attack by it instead.
-In normal combat, as the unit generally performs poorly due to low movement and having a fixed damage output of only 4 against anything with high resistance, so the AI most definitely shouldn't overestimate its capacity to win the fight. On the other side, if it would think this unit is very powerful, it would be confident and that might enable buffing it with a spell like Mystic Surge.

Overall, the arguments heavily weight towards the unit having a low rating - the same as now, or maybe even lower. In fact, it is the HIGHEST rated rare chaos summon, despite being the least effective in normal combat, and the easiest to kill, too. It most definitely should have a LOWER rating.

Night Stalker
This has 29 power.

-29 power is a joke, even for an uncommon unit. That's no better than a level 0 halberdier.
-These are either extremely easy to kill for human in lairs and towers, if they have access to death immunity or 13 resistance, or extremely lethal.
-The AI summons less of these than the much more superior and versatile Shadow Demon or Werewolves, but being an earlier unit, the chance of having this summon first is not that low and it's generally more relevant than Chaos Spawns.
-The AI likely should be scared of this unit on the overland map - attacking it allows the human to hit the AI with spells while hiding the Stalker in a corner.
-In normal combat, the unit generally performs fairly well thanks to the combination of gaze, weapon immunity and invisibility, however, if the unit is rated higher, the AI will be less willing to try to hide it which is often the better strategy (when there are units immune to death or 13 resist on the other side). Still, the enemy army will often have a mixed composition, and if the stalker scares too easily, it will fail to pick off the lower resistance units.

Overall, I think the arguments here point towers having to INCREASE the rating for Death Gaze.

Gorgon

Being the highest rated rare summon in the game by a fairly large margin, I'm sure this should stay the same.

Phantom Beast, Phantom Warrior
These have 0 armor so their strategic ratings will be low anyway, and considering how fragile they are, rightfully so. They are extremely easy to take out in lairs, which is the only place where they appear on the overland map, too. So raising the Illusion modifier is unnecessary.

Doom Bat
These have a rating of 151.

-That rating is slightly below Chimera's, however, this unit actually is weaker in combat than a Chimera against all but the high armor targets. It has less total health (30 instead of 32), and less damage output (8 damage instead of 4 figures attacking twice with a fairly high rating). Looking at only this, makes the Doom Bat feel slightly overrated - it isn't as powerful as 85% of a Chimera in most battles.
-It however has Immolation, which is not included in the rating but does better damage than Chimera's Fire Breath against most targets - so overall damage output might be on par.
-These are extremely dangerous for a human player in a lair and very hard to take out - and for that, they are worth a lot of treasure.
-Raising the Doom multiplier reduces the chance of an AI trying to flee with their Doom heroes, which might or might not be a good decision, but usually is - fleeing might kill the hero and if it's still alive it indicates the human has a hard time damaging it so staying in the battle might be safer. As losing a Doom weapon to the human is a critical loss, this is a fairly important case.
-Likewise a hero with Doom weapon is a huge threat if controlled by the human, and should be rated as such in normal combat.
-The AI most definitely should be scared of this unit on the overland map. Being the defender, it gets to deal damage to the attacker immediately on the first turn.
-In normal combat, the unit performs roughly as well as a Chimera but moves twice as fast, so a rating slightly above Chimeras might be the ideal.
-However a higher rating makes it less likely for the bat to try to "hide" and abuse it's high speed. Considering it can do guaranteed damage on offense, and is fairly easy to kill by spells, this might even be an improvement.

Everything seems to point at Doom needing a higher modifier.

Armor Piercing
This one is not trivial as there are plenty of units with it.

War Mammoth : these have the highest strategic rating among normal units, and by a large margin. Further increasing it would be very bad.
Air Elemental : this benefits immensely from having a low rating, thus triggering hiding tactics with invisibility and 5 speed. The unit is extremely fragile if revealed, and dies to almost every direct damage spell, as well as most attacks.
Paladin, Griffin, Elven Lord : I think the rating on these is fairly reasonable (35-50 on the base unit, on par with most top tier normal units)
Great Wyrm : This is fine as is but wouldn't be a problem if the rating was higher, as it's still quite a bit below Colossus.
Death Knights : Already having a better rating than Demon Lords, we don't want to raise it further.
Storm Giant : These are somewhat on the weak side, and could likely use a boost to their ratings, albeit it's not that important. In fact they are already rated higher than Efreets or Doom Bats so it probably should stay as is.
Pikemen : This would be a ton more powerful if it was a flat +4 instead of a 25%. Even if we keep the percentage, this is a primary target for buff stacking abuse, so raising the rating is a risk.

Overall I think keeping Armor Piercing as is is the best move.

[Nelphine]

Two notes: I definitely think great wyrm is undervalued. 
Pikemen would increase their BASE value if it changes, which is actually probably not a horrible thing. But the percentage scales with every buff they get. Compare flat vs percentage on elite mithril versions. (And once you start getting real spell buffs, the percentage makes pikemen go absolutely crazy).

A third note: I consider efreets, doom bats, and storm giants, stone giants all to be slightly underrated. Mostly a personal thing. Basic reaasonng is that gorgons are reasonably rated, yet gorgons have a very hard time hurting any of those other rares. Then again I'd like to see stone giants with 1 or 2 more ammo as well, as right now storm giants are flat out better.

[Seravy]

Efreets are underrated because Caster and Immolation are not in the formula, can't help that unfortunately. (The only real way to raise the rating would be to give it less ammo at a higher attack strength - but that's a fairly significant change in functionality, effectively making the unit stronger in normal battles as well.)

Storm Giants are actually not that great - what makes them good is the fact that there really aren't much units in the game that have a strong enough non-arrow ranged attack, and enough durability to not die to the Giant's attack (and melee units are at an obvious disadvantage against a ranged unit). Maybe having a higher modifier for Armor Piercing on ranged attacks could be a good idea - but again, the giant is already rated above most other rares, even though it's not actually better than them.

Stone Giant has the second highest rating among rares so it's most definitely not underrated.

[Nelphine]

Sorry, for stone giants I meant in tactical they aren't as good as expected, thus why I want to give them more ammo.

Storm giants, I completely agree with you. I'm just saying they need to keep the percent of armor piercing, as opposed to pikemen who would be more accurately represented with a flat bonus of 3.

[zitro1987]

You make good points about chaos spawn.  I no longer suggest an increase to its rating as I was making comparison arguments in my head against the wrong units. I'd say mid-100s is fine for them. The unit is also very situational and you smartly gave it a low research cost to account for this.

Doom modifier being 2.5X instead of 2X would be reasonable with doom bats probably shy of 200 points. The unit is scary in the right environment.

Stone Giant is the unusual case of a single-figure having a high rating. It's surely the 2-ammo element in it. The unit in tactical combat at the low cost of 275 handles itself well with land-link.

Efreets appear to suffer somewhat due to their high ammo, just like other powerful ranged units with high ammo (shadow demons?). A simple balancing solution for these kinds of powerful units is to slightly increase their ranged power while reducing their ammo to 6 or 5. However, the overall boost in strategic power would be too minor to be worth doing so.

[Seravy]

-Reduced Multigaze value in unit attack rating from 1200 to 900
-Raised Death Gaze value in unit attack rating from 300 to 700
-Raised Doom and Illusion multiplier in unit attack rating from 2 to 3

This moves Doom Bat to 227, Chaos Spawn to 134 and Night Stalker to 55.

...one thing however...what if this causes the unit rating on a Doom hero to overflow?
We've had crashes caused by that before and changed the calculation to ensure it won't go over the top even for a maxed hero. Albeit, now with the removal of Berserk, I guess that shouldn't happen anymore?
Someone should calculate a theoretical maxed stat hero and check if it will stay below 32768 attack rating or not.

[Nelphine]

Max stat hero will be around 70 attack, +.. 12 to hit? Doom and illusion (do they stack?) Armor piercing and thrown and first strike.

So [(70-2)+(70-2)]*20*1.25*1.25*3*3*4.99?
190k
Assuming you can't stack doom and illusion, less than 65k.

If you can stack them it doesn't matter if the modifier stays at 2 or not, it will still be too high. If you can't stack them you're safe.

Edit: oh, 32k limit. You can almost break that without doom or illusion period. Can certainly break it with a x2 modifier, even if you can't stack.

You want me to work exactly what the issue numbers are, or are you fine saying that combination of abilities is completely unlikely to ever happen?

Also, I wouldn't reduce chaos spawn quite that much. They're still nasty. I'd aim for 150 rating.. so multigaze around 1100 or 1150?

[Seravy]

You can't stack doom, illusion, or armor piercing. First strike does not stack with Thrown, it only applies to the melee part.

Don't think I've ever seen 70 attack on a hero though. 50 something was the max. How do you get 70?

I don't want the Spawn to be higher than the Efreet.

[Nelphine]

Paladin or Black Knight with Might and Super Blademaster, level 10
10 base melee +10 level +10 might
+6 to hit
Weapon with: Doom, Illusion (or +6 melee if they don't stack), +3 to hit, Shadows
Armor with divine protection (+1 to hit)
Misc with +4 attack
Stacked with Holy Bonus 2 (+2 melee)
Holy weapon (+1 to hit)
Flame blade (+3 melee, +2 thrown)
Lionheart (+3 melee)
Chaos Channels
Stacked with Level 10 Necromancer (+3 to hit)
Chaos Surge*5 (+11 melee)
Land linking (+2 melee)
Survival Instinct (+1 to hit)

= 55 melee, 54 thrown, +14 to hit, first strike, armor piercing, doom, illusion

OR

61 melee, 60 thrown, +14 to hit, first strike, armor piercing, doom