Why not? What do you find "silly" and "gimmicky" about the Prometheus? Is it the fact that it can split into three ships that act together in co-ordinated attacks?
Yes. What's the point? If you need three ships, then build three ships. If you need them to be in one package, then have one large carrier ship that can disgorge the other two as needed. Something that's designed to switch between being a single ship and a small fleet is not going to be especially good at being either one. There's have to be too many structural and design compromises. Either the redundancy of features for the three ships would make the single-ship configuration unwieldy and wasteful, or the separate ships would be incomplete and weak.
Besides, what happens if one of the three divided shiplets gets crippled or destroyed? That would make it impossible to put the whole ship back together as a functional unit. That strikes me as a pretty serious Achilles heel -- lose 1/3 of your force and you basically lose the whole thing.