True, although the way you get superior production in the first place is by applying strategy to get more resource expansions than your opponent; send forces to a mineral area too late and the opponent will already be entrenched, but send them too early and they won't be able to hold on to the region when they get there.

I always have/had trouble with that aspect of it, so I make up for it by hiding single units all over the place in the endgame so my opponent gives up. :)