Well, if you're going to replace something, replace it with something that doesn't match the players' races.
I've been thinking about this option, and there's something to it, especially in light of the recently discovered problems with the area under the console – it also needs to be leveled, which isn't ideal.
And it's not entirely clear, even if you're playing with different races: you build a couple of dozen of your level 6 units, and your opponent has the same opportunity – what's the problem? The problem is that someone did it faster – that's just skill, learn to play.
