Are you calling God a fool? God commanded Israel to do this and for very good reason.
Yes, to the Canaanites. Not to every idiot who tries to agrandize himself by alleging that he’s a Canaanite. A very holy rabbi once implied that Germany was the nation of Amalek. As holy and revered as he was, it would be halachically forbidden to wage a genocidal war against all Germans based on that statement. Empirical proof is required, not bald allegations.