This is my first post as a member of My Crysis.
In Crysis 2 the classes of foot enemies was severely limited, the only two were the snipers and the generic armored Operators. Sure, the Cell all had different guns, but it got boring and repetitive to shoot at the same silver guy after a while.
Snipers were used rarely, and the vehicles worked less as ways to free up the space, and more as a boss battle or a driving section.
In the Dam busters gameplay the suit visor list the green enemies as "CELL Recon" and the Black enemies as "Troopers" which might indicate that further along you fight snipers, heavies, turrets, vehicles, troopers and recons, all with different AI and group dynamics. The fact that only two units have been shown so far is worrisome, but I think it will get more soon enough.
I also think it would be a good Idea for groups of the same unit to stick together, and have leaders. Large groups could form "Platoons" with recons at the front, troopers in the middle and trucks at the back.