Well, the main problem with that is that buildings are way stronger than units, with the drawback that they can't move (obv not a drawback in this mode).
So the strat would pretty much become: choose the right combo of buildings and wait. Also when you have things like church of negation or shadow worm, things can become trivialized....
Probably the most interesting way to do this would be to arrange the terrain in such a way that buildings can't be spawned everywhere, turning it into a kind of battleforge tower defense?
