Picks are public! Short story: Competition is tough!
TBS - Mao (EXP/PRO) of Carthage (Fishing/Mining - Numidian Cavalry/Cothon)
I hear TBS listed among the strongest players. I haven't seen much Civ 4 reporting, but I played against in the Civ 6 PBEM 17 and you can read Sullla's recent write-up of his excellent performance there

EXP will save a pop when granaries are whipped (or maybe hit pottery first and slow build while researching BW?), while PRO will be an immediate +2 commerce/turn from T0, assuming he also gets 2 cities connected by rivers. That is more than 10% advantage over non-PRO and will add up quick in the early game. However I am counting on PHI for later lump sum bulbs rather than steady trickle. Numidian Cavalry are scary simply because they counter the standard Spear defensive unit. The only way to right them seems to be strength 6 units. If I neighbor Carthage I'll need to carefully consider heading to HBR myself to ensure I'm not a tasty target.
Cornflakes - Nebuchadnezzar II (IND/PHI) of the Dutch (Fishing/Agriculture - East Indiaman/Dike)
I really like the leader and look forward to playing IND/PHI combo. Cheap forges erected early are enough IMO to make Industrious pay off. Generally I don't like chasing wonders until after all land is claimed, but on a smaller map I expect to begin wonder construction earlier rather than later. Likewise I expect PHI to massively accelerate the mid game. The civ selection was somewhat mediocre. Nothing really stood out to me (see my waffling through nearly every option at the last minute). Ultimately I'm looking to make a decisive move via sea, and PHI can help me reach that target early. I'll have an entire era of naval dominance, where my enemies will have to defend entire coastlines without any viable counter on the seas. The challenge will be remaining competitive early without much of a development boost. However Forges can help close that gap. I intend to get forges online ASAP and thereby achieve 25% production bonus towards all builds. Also, Pyramids will power the economy in the short term while filling up the GPP bars for super-charged mid-game . Unlike PB43, the win condition this game
IS building all the wonders
Mr. Cairo - Catherine (CRE/IMP) of Khmer (Hunting/Mining - Ballista Elephant/Baray
Catherine is a fine choice however not my first choice for this advanced start setup. I feel like the expansion-oriented traits are devalued and therefore prefer economic traits for this setup. Khmer keeps full strength Ballistaphants which target mounted outside of cities. That is a strong scary unit which can't even be countered by my own war elephants. Pikes are really the only counter, but the Ballistaphants are still deadly to a combined arms stack since they will target knights instead of the pikes. Good think I can bypass and attack via sea! Mr. Cairo does not strike me as an aggressive player, rather more likely to take a slow and steady approach.
Commodore - Washington (EXP/CHA) of Ottomans (Wheel/Agriculture - Janissary/Hammam)
Commodore, on the other hand, is the opposite of Mr. Cairo. There is no slow and steady. Any immediate advantage or perceived future disadvantage is impetus for action! Synergy in the pick for boosted UU, lots of happiness (which looks good, given the apparently sparse resources). Commodore is a big fan of CHA and in RtR I completely agree due to the +1 XP from colosseums. However that didn't carry over to CTH. Happiness is key though to maintain growth (and whip capacity!). With Ottomans he's looking at a later power spike which bodes well for neighboring early.
AutomatedTeller - Stalin (IND/AGG) of Japan (Fishing/Wheel - Samurai/Tatara)
Another IND leader

Now I have to look over my shoulder for wonder competition. Good news is that PHI gives me a leg up on Pyramids, and later game AGG doesn't do anything for the economy. Therefore I'm likely to have a lead in chasing later wonders simply by unlocking them earlier. AT rolled about half of the remaining IND leaders and chose the least economic of his options. Japanese UU got a makeover and now provides +2XP to melee. AT doubled down taking AGG for a warlike combo. However this combo looks like it will fizzle out in the later game. Not a good neighbor early, but hopefully my neighbor's neighbor

I don't know much about AT as a player. We faced off in PB9 where he developed well, but quit after I took out his capital and another wonder-city with a commando strike (hmmm ... seems to be my signature move?).
Scooter - Wang Kon (FIN/PRO) of China (Agriculture/Mining - Cho-Ko-Nu/Pavilion)
Scooter knocked off the rust with PB50 and is ready to come back with a vengeance

Unable to decide whether PRO or FIN provides the best economic boost, he decided to claim both! This will provide a steady
trickle stream of commerce in the early game, growing into a raging river if allowed to develop unchecked. Unhappy with the Crossbow change from the PB50 version of RtR granting Cho-Ko-Nu to everyone, scooter decided to claim the monopoly on collateral-crossbows. CKN are a nice bonus on a map which I believe will be decided via naval assaults. I need to mobilize my East Indiamen earlier rather than later. This is another slow-starter combo benefiting from Advanced Start, which will become an economic powerhouse late game. I suspect that I may have to prosecute a similar decapitation strike if I see Scooter running away economically.