If it is open to all units found in the editor.. then depeneding on the value you give to them, I would want 2 predators, 3 warbots, An Odin mk2, the rest of the numbers in nova type goliaths. As for the air 2 nova type Raven 2s, 3 sci ships, one cruiser (I.E the pirate cruiser) and the rest in wraiths. If you can do it maybe let the player select the units before the map starts. I have seen that in the map I am trying to bring an updated version of out. In that map you got 4 choices Bio, Mech, SCV, and Mix.
Also if I said SCV would you let it build any defense buildings like bunkers or turrets. There is a unit in the editor call the Kel-mon Worker or something close to that. And they can only build a few def type buildings. Also there is a unit call the drone operator that can be found that is another unit that would be fun to use. Just depends on what dependences you load in. I got a map where I am working on a tech tree and set up for all the units found for terran right now. You may wish to do something like that, that just has the units mixes you wish to look at or just to hunt for all the units.