)
(look if you want to mount a gun that a helicopter can actually carry on a helicopter, that's genuinely fine, if you want a helicopter that carries a fortbreaker that won't fly, if you want to have a siege air battleship carrying a massive cannon that has to be loaded with genuine boulders i can accommodate that, but then i will hold you to it having an exploitable weakness.)
it's kind of an honor system, you can theoretically do what you want, but in practice i expect it to be kept reasonable.