Yeah it migt be a problem
I didn't notice the trigger maps are embedded without separable files for online play, makes sense.
I was thinking of Sniper CTF or bomb plant/defusal with random groups of NPC units moving around the map to create danger for both teams, as well as runes so you must send spotters first, with each round you can buy fire throwing grunts, additional spotters(submersible peon), demo team etc, or air strike (temporary battleship or catapult with 128 range and turtle missiles), etc, the random factor makes each round different as much as is possible, random terrain would be cool but maybe a bit ambitious.
I think random can be implemented another way (Hp of unit under some effect) but it's slow, you lose player slots and I don't know how reliable that method will be generally.