I just think that the mantaman looks good as is. It's got a nice alien design, with good animations, that's not really asking for an improvement. I didn't feel like putting in the effort to redo it as is. (Also, its wings seem like an arse to animate.)
I don't know what's going on with the gnaar boomer. It's literally the same code as the others.
The dragonman is kind of irrelevant, since the devil stallion can already be considered an improvement of it.