Many people will say to have actualy 3 commands, but this is kidda unpratical, like Agreesive and Passive. it,s interting to have instead of. 3 commands, 2 of then.
Prone,
Crouch
Stand
have
Dinamic (they will stand in the same position that you [alerdy in game], since if you are in prone they will be in prone, if you are crouch they will crouch, like what we have in the game alerdy)
And
Duck for cover (or whatever name), that they will take cover and ramin has litle expose possible,
the deanimic will be interesting for moving around, while duck mode will able to stay and better defend one position.
it still considerable hardcoded, but a advance anyway.