Yes, it's on-topic.
It's about material for a Role-Playing Game, it requires RPG expertise to answer well, it doesn't fall afoul of our rec-categories that've been judged off-topic.
They're just not good questions.
Questions like this have a lot of fiddly little bits, require a lot of work to answer well (as @daze413 has done), and are of limited utility down the road.
All of these factors act as natural rate-limiters: the question's not getting many upvotes, so nobody's getting a signal "post lots more of these, you'll get all teh pointz!" And it takes a while for answers to come in, if at all. All-told, we only get a few balance questions a month.
But they are good enough.
Good answers do teach future readers something about how to analyze the balance of their homebrews. So let 'em live, and they'll sit in the long tail of questions that have limited utility and poor reward-effort ratios.