User blog comment:Henshin1971/The Showa counterpart of Ultimate Force Zero's member/@comment-1733689-20130830131629/@comment-5527544-20130831101917

I think Teridax is right, Jumborg Ace got his name from the Jumborg plane with Ace added to give him a name, Jumborg Nine just follows his name like the other Ultras follow Ultraman's, nine is probably from the car model.