at any income?Why is that?If I would've earned enough why wouldn't I sponsor him, I am not sure I got what you mean
You don't qualify to sponsor your brother because you are married. You would only qualify to sponsor your brother if you were single, had no children, both of your parents were deceased and you had no family in Canada (i.e. no aunts, uncles, etc.).
If your brother wishes to immigrate to Canada, he and his wife will have to qualify on their own through an economic immigration program like Express Entry.