Basing this on actual animals? Cats will actually fold their ears down and back to protect them in a fight, or when they’re feeling threatened. Theoretically you could probably still grab them, but it wouldn’t be any easier than going after a human’s ears. Also, having your ear grabbed in a fight sucks. Just putting that one out there.
Honestly, if you’re going to write anthropomorphic characters, you should probably spend some time studying the animals you’re using. Fortunately, there’s nothing the internet loves more than posting pictures and videos of cats.
Also, if you want a reading reference for anthropomorphic characters, I’d start with the Redwall books by Brian Jacques. It’s been years since I read them, though, so I honestly can’t remember if there’s any cat characters. (I think so, but… I’m not sure.) Also, it’s worth pointing out; Redwall is about anthropomorphic animals, not humans with some animal features.