Roman Leather Lamellae Scales from Karanis, Egypt

[Renatus]

The Romans were rather down-to-earth, literal and essentially prosaic in naming things and people

Indeed, and (at risk of labouring the point) one of their methods of indicating a person's area of expertise was simply to add -arius to the object of his expertise to show his association with it, e.g., sagittarius, ballistarius, retiarius, etc., etc., etc. We have established (I think) that clibanus can mean 'cuirass' or 'oven'. Thus, clibanarius could mean 'associated with a cuirass' or 'associated with an oven', i.e., a cook. As you say, take your pick!