Well to be fair, they are and when ships started out it was a simple “buy $800 ORCA to kill $12,000 battleship”. I used the banshee when it was a ship sieging our base and it’s Guns were focused on structures. This allowed me to reload fairly ok time and move fast hit and runs on the ship while it’s guns went from buildings to me back to buildings.
it should be noted however that ships are incredibly expensive, slow and need to be countered with team work. The aiming on them against ground units is also questionable from range. I believe different tactics need to be made as the previous ones were not working. I also believe it is hard to give reason that such an expensive unit cannot kill an $800 ORCA Fighter or Apache.
The destroyer is a bit more OP than it should be for air though with the missile it fires (I believe at Aircraft). So I can see toning that down a bit... but it is weaker and meant to serve as support, not building destruction.
For the battleship, I think it should kill ORCA’s no problem. It’s massive, tons of guns and against land units it’s not all that great. Hell you can just get a battleship to fight against anouther if you’re that worried about it. If you don’t have the $ for it then you’ll realize that’s what this game is about and hope be better prepared next time.