I give comms to the players that left the best impression on me, I don't give one to a player just for playing their class, its really pompous to expect comms just for healing.

Don't expect them, they are a nice bonus for a job well done, expecting them is kind of a bad attitude to have. I mean if every performs well, players still have only one comm to hand out. Yeah getting no comms for turning a run around or carrying everyone else is annoying, but at the end of the day, there isn't much you can do about it.