Play many games, Eric. Play Apocalypse, play 2000, play 1500. Use everything in that list multiple times in multiple settings and get a feel for how everything works alone and how it can be supported. When you are playing a game of such grand scale, you need to be able to look at each unit and instantly realize what it can do with that you're given in a turn. The size hasn't been determined yet (I'd like 4-5k per player... or per me), but until then use everything you've got as you've been doing and keep at it.