Will you ever play either of them? I don't see any reason to do it and I don't see any reason not to do it. Maybe just check the bye week matchups of your other guys and go with whomever has better match ups.
Yes, drop Crabtree for him. Even if you don't play him outright, you also can consider which of the two would you rather go against if an opponent were to grab the player? I'd much rather go against Crabtree than Cole's ability to explode, which means I'd rather own Cole.