Ok but in how many stories has there been a member of the other team switch sides to help the protagonist. something to think about!!!
Yes, fair enough, however, even if they sided with Dovahkiin, these dragons seem... I dunno, kind of like the wouldn't much care for being ridden like an average horse. Then again, I've not really learned much of their personalities, but that's my assumption. Anyway we supposedly have that Thu'um ability which will summon a dragon to help us or something of that sort, so there may be one or two who to help the protagonist.