Casulties of WW1: about 11.000.000 (11-15 mio estimated, without further casualties)
Casulties of WW2: about 60.000.000 (60-90 mio estimated, without further casualties)
Considering numbers, WW2 was more of a slaughter war. WW1 is still considered by historians that altered the lifes of many countries to come.
There is indeed risk involved taking topics which have not been fully explored to gameify real-life stories and events to fit the mold of intended game-play of a video-game. One never thought WW1 would be an interesting topic for a FPS, yet a popular company managed to adapt it, albeit a bit artistically, whilst being rather fun. WW1 also had quite a few war changing mechanics, e.g. the introduction of the Lincolnshire boiling water on wheels tank.
And it seems to pay off for that company, considering the pre-ordering numbers being rather high and other companies intending to explore the WW1 theme.
Some offtopic, sorry.
Er... Slaughter war... I meant not by casulties, but by... maybe "style" of war itself. Don't know, how to explain it better. That was some kind of "transitory" type of war - in-between of old "wall-to-wall" war (last of them was murican civil) and modern war.
My point about it was, that CoH series strategies are mostly about "unit (micro)control & saving" in game. But... WWI wasn't that war, where sides of conflict cared about losses too much. We could say same about WWII, but... it's more "modern", so - saving manpower was actually important. + in WWI there wasn't such big number of combat vehicles, different type weapons... It will be pretty "poor" strategy, if they will do it, I suppouse. But, that's my sight on it... maybe Im wrong.
P.S. Battlefield 1 hype is not that understandable for me... It will be just another "battlefield 3" in other decorations. Or maybe "Battlefront" in WWI, which is worse. Whoever expects it - it won't be great, I can say it right now for sure. Don't pay to EA and their enslaved DICE anymore, they don't deserve it.
P.P.S. If CoH 3 will be about WWI - Im 100% sure, that they will add there some "gas mechanics", cos in WWI different chems and gases used pretty often in combats. It will be innovation, like Cold Tech in CoH 2. And my forsight - people will whine, that "it makes game more difficult, for no reason, remove it pls, we are reatards!", like they did with Cold Tech...