Mind that if the number of vetoes goes high enough you will actually have to play on the vetoed ones - becouse the other player will veto the other half.
Some maps, like Faymonville for instance, will never be vetoed, because they are actually good maps. Other ones are unbalanced to a crazy level, either side-wise, faction-wise, or both(Lost Glider, La Gleize Breakout, Caen...). Adding maybe 3 more vetoes would be enough, just to get rid of the worst ones.