it takes lots of arrows to kill something.
Well I'm not sure that is true. I usually kill cliff racers with one even on difficulty 100 although my Marksman skill is only 56. My combination of Auriel's bow and Daedric arrows helps. And I'm not sure that it is realistic to kill with one arrow. It must depend where it hits. St Sebastien was skewered by a whole quiver of arrows before he snuffed it. Perhaps the kwama forager has a hide like an elephant, maybe it can only die if you hit a particular organ?
I'll dissect one in the lab next time I find a good specimen. (Maybe one of you on the forum already has? If Theta's kids has got hold of one, she probably knows.)
But there are lots of strange things about Morrowind as you say.
BTW are you suggesting that you wish beasties were easier to kill? Most gamers enjoy the harder battles more than the easy ones. For my own part I would prefer fewer but tougher creatures.