Well, if you're stuck in one place sure; but we can wormhole to other galaxies in the lions. And, since we're fighting in space most of the time, the maneuverability comes in handy.

They were built over 10,000 years ago by a race has been almost completely killed of; it's not like I can ask why they chose this design. The cat thing is a bit strange after all. [ She adores Green, but why lions? ]