game stats aside. you cant ignore what ive said earlier about the crippled state the nords are in after the war. you should also watch this video on the altemer.
www.youtube.com/watch?v=vjSHw_… dont underestimate them. plus just because hammerfell fended off afew of them doesnt mean the nords can take them all down. remember the oblivion crisis? and how the argonians made the daedra run away by themselves? yeah, the argonians of blackmarsh did it on there own but it took combined forces for pretty much everyone else.
and i want you to put this in perspective, the stomcloaks are pretty much the nordic supremisist that are not accepting of anyone else, be it elf, man, or beast. they're pretty much just like the dominion but in a different skin. and ulfric likes to keep it that way. and the fact that through the main quest it's shown if some books at the dominion party that ulfric's rebelion does nothing but help the dominion get closer to owning skyrim.