While it’s still under the RTS side of things it’s not really known outside of the fabase so I would suggest overhaul mod Dawn of War: Ultimate Apocalypse. It’s a heavily modded version of the original Dawn of War games and is quite fun. Ever wanted to drop nuclear artillery on your friend who’s chucking mecha at you? How about air dropping what amounts to a Maus but bigger into the rear lines of an AI who’s pissing you off? You can do that and more with this mod.