It isn't necessarily wrong. It isn't necessarily correct either. It quite simply depends on how well the factions are designed around the concept of possible mirrors. Judging from what I've heard from people that played the alpha, it wasn't really an issue. Which is why I'm relatively optimistic towards mirrors.
And authenticity? I honestly don't care. Lacking authenticity never ruined Age of Empires 2 or Call of Duty 2 multiplayer for me. I get that some people actually get these kinds of games because they're somewhat historically accurate, and while that's fair, that's what the single player campaigns are for in my opinion.
Also, chess would've been mirrors if it wasn't for the fact that it's a turn-based game and thus asymmetrical by default. :V
Any FPS multiplayer is completely different from any rts, and, as far as I am concerned, cannot be compared. The thing about Starcraft 2, Age of Empires 2, or warcraft 3 is that immersion and authenticity are not key components of them. They are however essential to what makes company of heroes a unique and outstanding game.