Battlefield isn't good for tactics unless those tactics are "run about like a loon, don't follow orders and for Gods sake don't play as a team".
The ORIGINAL Operation Flashpoint is a proper tactical game. This is after all what spawned ArmA (for those that don't know, the studio that developed OpFlash and the publisher fell out, one kept the name the other kept the anal attention to detail and massively steep learning curve).
OpFlash is very free roaming too. Dragon rising is a little bit more "on rails" in terms of the campaign but that's not always a bad thing. Red River plays pretty much like any other sort of tactical shooter to be honest. It is good fun though.
If you want to learn team play, have a look at the early Ghost Recon games and the early Rainbow Six games (Particularly Raven Shield which is awesome).