Some cool stuff here.
From gamespot vid:
Even riflemen have the *100 modifier to the reported strengths in melee combat. Reported strengths are 2875 vs 3125.
Injured swordsman vs near-dead pikeman is 3040 vs 670
[Supports my theory that these are just to avoid decimalization]
Combat outcomes are not rigorously reported (at least in the simplest UI mode; might be changeable through options); instead "stalemate" or "major victory" or "total victory" or similar are reported before combat starts.
3 destroyer bombardments (with promotions!) kill a battleship.
Accuracy vs barrage promotions, one (accuracxy) gives +25% bonus ranged attack against units in open terrain (NOT hills, jungle or forest), the other (barrage) against units in rough terrain (forest, jungle, hills.
If I had to guess, I think so many of the complete kills might be coming from the fact that units seem to be heavily promoted. It might well be the case that promotions boost strength/damage, but not health.