Yeah, Jamez, but there aren't a lot of choices then for GB's and Cruisers. Most of the weapons I use on a gunboat are either Cruiser or Battleship because, well, gunboat weapons suck. On a cruiser I use Battleship, cruiser AND gunboat weapons. And on a Battleship... Well... I haven't had a BS in a while, so I don't know what I'd use.
You cut the diversity of weapons for capships into thirds.
Personally, I think its fine the way it is now. It took two battleships using gunboat FG's to kill one battleship. That says that the battleship weapons are still more powerful. Plus, gunboat FG's are incredibly hard to aim on a battleship, even against another battleship. I put six on a Nomad BS for fun, once, and I could only hit NPC battleships that were sitting still and only after a few tries...