All games have a meta dude, if that's the most effective thing to do to solve your problem in 3v3/4v4, then do it. There have been useless commanders since day 1, but really when they released it there were more viable ones (I was a Joint Ops fan for a long time, lol.)
No way. USF should receive some special care like sudden flame nade from Relic to deal with garrisoned troops. You simply can't answer why OKW players must have that kind of special care but USF player must stick to doctrine. And it is not even an effective thing to solve the problem but just an opportunity to have some kind of fair battle after choosing the one and only commander with early garrisoned clear option.