I've noticed it too, and do in fact find it extremely amusing. Watching a newborn cub attack a fully grown lion and then for some reason being able to survive all the attacks and then kill the adult is just brilliant to watch.
I saw it just yesterday. To be honest, if a litter of pups were fighting (let's say the strongest was picking on the weakest/smallest) there could be a chance of the youngest dying. But animals that are under the age of 9 months would need a lot of help from an adult that was near by. Or if there wasn't an adult, they would be forced to run.
Ah, the ol' friend "powerplays" trap - almost all my friends that I role-play with powerplay.
Now, most of my characters are scrawny weaklings (I just favor that body-type since I'm a scrawny weakling, I know how to use it better) and are definitely aren't going to be able to take that much damage. But, when I do role-play fights, I try to be heavily realistic, it's just the way I am with my role-play; if you role-play a human, anthro, whatever humanoid, if you can't do it, then your character most likely can't do it.
My friends' characters are, more often than not, are a little thicker-skinned, though based off of them (like a persona, so to speak) - they'd probably be able to take a little more damage than my character, though if I - for example - "stab through their armored skin, killing them instantly" (which isn't something I would do, since it's not realistic), they'd probably be really upset with me, since I just killed their character.
I can't stand when a person is upset, be it stranger, foe, or friend, if they are crying, I will feel heavy guilt and probably start crying to. Why I bring this up is because that's what I do, I let them "kill" my character - or at most, knock him out/down - so they're happy. Even if it's not properly teaching them how to properly fight without winning, or even how to do it realisticly (I say "teach" because they like to write stories and whatnot, and I'm sorta like their teacher, so to speak), I still do it.
I do it in-game, any role-play with younger or less experienced people, and sometimes real life. Now, I don't go to Bonfire very much (but when I do, it's normally on Batter), or really anywhere where the pups or full-grown powerplayers can get to me (though I've had a few attack me and my friend because she called their wolf characters "puppies", though they eventually left us alone in a matter of seconds), but I normally let them feel triumphant and like a winner whenever I do bump into them - atleast whenever I want to role-play.
-Wolfie