OK I found something I don't like about Unreal .. it appears that Unreal's character movement component only lets you use *one* (and ONLY one) collider on your character - a capsule. If you want characters that need multiple colliders or shapes that aren't a single, upright capsule (like, say, a dog) then you're modding the engine, writing your own movement component or you're doing some nasty collision hacks (as far as I can tell). Urggghhhhhh.