One thing:
Even after a bunch of time with the game, I'm *still* honestly not sure just how population actually works, or what it does. No idea at all. I look at the population counts, and it's like.... yeah, those sure are numbers, all right.
Better explanation of that aspect would help.
Also, give the players some examples of what Smite can do in relation to these buildings. Like, if you want to halt the barracks producing units for a time, you can simply Smite the butcher, which'll put a hold on it. Or even smite the barracks itself. Very useful thing, smite. I've found it to be very versatile.