Depends on what else you have, do you need a high CP defender? Honestly dragonite is not a great defender, but since the gym scene is dominated by CP, you need high CP defenders so that you don't get stuck at the bottom of a gym and get shaved from it.
Having said that, it's really not a bad defensive moveset, but if you don't need him rigth away, you might as well wait for the upcomming gym rebalance and see how things turn out.