Well, there could be items for claws, whiskers, collars, puffy tails, fur and such.
Lions are felines, and a cat model isn't really worth it in my opinion.
And who knows what Kov might think of this honestly.
It's a good idea honestly, but lions are already cats, and you can make it look like cat.
Though the feline model's faces should be edited, so people can make more cat-like faces, know what I mean?
EDIT: I also think Kov only wanted the wolf and lion models for the game, and made cat and dog ears for a reason.
We can be creative with those models, too.