Battle servers exist to STOP the latency of one player carrying to the others. In this case US players might get a tiny edge over European / other region players.
Can't say I've noticed any command lag since battle servers a European player although if I played more single player I suppose I might.
The servers have vastly reduced drops /lag and broken games and were essential for the future of the game. A solution such as having a European server would split the small player base are and cut me off from all my US buddies.
For anyone who's played a lot of COH1, SC2 or any other game where you can get low latency, COH2 online play feels sluggish.
This could easily be done without splitting the player base. Simply route traffic trough the EU battle server if two europeans are playing against each other.