Backups least fluent would be his out. His most fluent however would be his weaving whether in poles or between my legs, his go out, his spinning left and right, and his finish around. Basically any fun motion behavior and B is reliable but he has a lot of trouble with slow and mundane things, except he has a rock solid stay in any position- thus the gumbi nick name. Then again he will throw you for a loop any given day with a new quirk so you never know what you'll get.
Arnold would be most fluent with heel, leave it, speak, get your ball(trained, he has no ball drive), and step back.
Sloan is pretty dang reliable in everything. She broke her down for the first time ever recently though so I'm cautious to say too much.