Hmmm, not sure really. Is the difficulty level different, or perhaps he's running some mods?
Civilization IV: 21 (Bismarck of Mali), 29 (Mao Zedong of Babylon), 38 (Isabella of China), 45 (Victoria of Sumeria), PB12 (Darius of Sumeria), 56 (Hammurabi of Sumeria), PB16 (Bismarck of Mali), 78 (Augustus of Byzantium), PB56 (Willem of China)
Hearthstone: ArenaDrafts Profile No longer playing Hearthstone.
Hearthstone: ArenaDrafts Profile No longer playing Hearthstone.

I think you lose soldiers if you don't give them supplies, but it might be cheaper to reinforce them back to full strength later than to supply them continually before 1939. Although from that picture you might have more IC than you can spend on production anyway? So maybe just drop some consumer goods.