i guess i am filled up with suggestions
1- make the player and the enviroment interactive between them, if its raining, id love to see your vision going blur because of the water, same with snow and dirt
2- let the AI do the same things player's do, support fire, smoking, and make them act just like real life players
3- let you chose the different skills for the AI, dont just select their inteligence, make it so you can chose, for example:
a) their FOV (not every soldier have the same field of view)
b) their weapon's control (depending from every weapon)
c) their speed, either running or their agility to swap weapons or change stance
d) how smart they are.