Usually when a game is decided early or it becomes a stalemate of who can spam the most heavies theres a gap of what you can do to end the game, so what if something like super weapons were implemented as GAME ENDERS. (I wrote this at 2AM nuff said )
We already have game enders: HIT missiles, railguns, artillery. Once you have those, you don't need anything else. If both teams have them, one team is going to run out of resources very soon; victory is inevitable. There's no such thing as a stalemate once heavy tanks are on the field. Plus, superweapons are banned.
actually heavies cause stalemates because they are hard to destroy and most people do hit'n'run with them (especially true for nukes)
Age of empires had the "wonder" system that would end the game if a masive building was finished. perhaps we could copy this system to the same effect.
Where's the fun in that? It would just be winning for the point of it. Nuclear ICBM Silo would sound a lot better.