I agree that more padding wouldn't hurt.
If I were hauling airplanes long distances in a rack, I'd make soft cloth wing bags.
Check used clothing stores for thick cotton pajamas and sweat suits, cut the legs or arms to suit, and sew the wing tip end shut. A single string tie at the center will keep them from pulling apart.
Pad any contact points with an additional layer of bubble wrap. Bubble wrap might stick to paint, without the soft cloth protective layer of the wing bags.
Amazing how much hanger rash airplanes can pick up in transit!
Bill Adair