Just because a ninja may be a bit smaller than their comrades doesn't mean they are any less capable in a battle, especially in the world of Naruto where the existence of Jutsu and inherited techniques means almost anyone can become a powerful ninja, regardless of their appearance. In fact, some of the deadliest ninja in all of Naruto happen to be pretty short, so it just goes to show that height doesn't mean that much in the grand scheme of things.