I really would like my dragons to behave differently based on if I'm handing them in mele or ranged or spells, and change to try and avoid my stronger attack potential, giving them more health is like giving a bandit more heath, if I can find a way to quickly kill then consistantly I'm going to do just that, but although I think dragons shouldnt be able to be killed by anyone but the dragonborn, I dont think they shouldnt get their asses handed to them by something that can't legitimately do it to a smarter dragon but after they lose should run away and despawn or not flop down and die forever, but only be permenently killed by the dragonborn absorbing their soul (like in the lore) which could be triggered by making the dragonborn actually have to do some damage or have the killing blow (maybe get down in a crawl for like essential npcs do for dragons that gets knocked off by a player damage conditional).
Dont need deadier dragons, need smarter lore friendly dragons, because if your truely having to use skills you dont normally or use your skills better to have any chance, I think that qualifies as a grand challenge.
I'm not sure anyone has done dragons well enough yet, mostly because I dread having to grind through dragonfights, also dragons on the ground are complete idiots, you stand there slicing at its side while all it does is slightly wound you with its wing or something, epic dragon fight, it actually moves around more then its head, moves its body, and is generally more like awsome dragon fights... instead of fighting a flying cow or something.