The problem is that a large universe with lots of options is really hard to balance with the focus of a tournament. The more options your opponent has, the more thinly you have to spread your forces. "What if he takes artillery? What if he takes aerospace fighters? What if he takes hordes of infantry?" The winner of those tourneys ends up being the guy who won the rock/paper/scissors contest, and loaded up on something no one expected.
I'd suggest something a lot more simple, and easier to implement. Each side could have a certain number of support points that you spend before the game, sort of like some versions of 40K had strategems. Like maybe you get a support point for each 750 BV in your force (or whatever). And maybe one point gives you 3 artillery shells a turn for 4 turns. Or it could give you an aerospace bombing run. And perhaps each 1500 BV gives you a "response point" as well, something you select during play.
So if Bob is playing a 3000 BV game, he could really load up on artillery, taking 4 barrages. So he can get 12 shells a turn for 4 turns, or 3 shells a turn for 16 turns, or however he wants to divide it up. But then Rick decides to spend one of his two response points on "VTOL Counterattack", which hammers the artillery.
The trick would be to balance things so the support point/response point thing doesn't become the focus of the game. If done correctly it could counter tabletop spam with things that should be available in universe. It doesn't really make a lot of sense that my mech lance would somehow wander into a giant horde of infantry out in a field somewhere, completely unaware. Why wouldn't I have seen this coming and brought some artillery support? Or at least loaded my ACs with flechette ammo? The reason in real life is because I didn't get to see your army list until it was too late to change mine. Some spam-counters might be a good idea.