As you may already know, the two new turrets, Polyps and Howlitezers, came around after all the bosses were made. This means you don't see them in any of the boss dungeons (except for RJ boss fight, which was updated). I think this should be changed a tad:

Snarby: Some Polyps and Howlitzers, but Gun puppies don't match too well, IMO.
Royal Jelly: Polyps, Polyps, and more Polyps. That's all. :P
Roarmulous Twins: Keep it the way it is. It's a robotic boss dungeon, no?
Vanaduke: Replace Gun puppies with Hellhounds (See below)

I said up there that FSC should have a new turret. It's nothing big. Just a Howlitzer that is covered in flames. The Smoking Howlitzers shoot bullets, so including them instead of Red Rovers would remove the bullets. Hellhounds would shoot fire the same way as Red Rovers do, but in addition, the skull missile could trail fire. (Though this isn't related, including Deadnaughts in some places instead of Trojans would spice things up, too.)

Meh, mostly pointing out something in our most played levels.