Remember that the Behemoth's aren't slim or short enough to fit through a normal door frame. They're large enough to knock out walls, not just putting a hole in a wall. Even a tall but muscular body can stoop to go through a door frame. Angel and Kalani's tactics wouldn't have worked on anything but something really huge.
Skittles also said that they can't climb. Anything muscular with normal or abnormally long arms would be able to climb with ease.