Marty Robbins and Steve McQueen raced under their professional names.
I notice he's listed on all ARCA documents as Garrett Mitchell - entry lists, practice speeds, Q order, etc. NASCAR could have also insisted he use his given name. I think they should have, but apparently they don't have a problem with it.
Between losing the charter lawsuit and finally acknowledging their decade-long playoff experiment wasn't working, one very part-time driver's name doesn't make top ten on the Ridiculous Appearance list.