as said before, nearly all garlean names are from Latin, even their ranks (medicus[medici], hoplmachus[hoplomachi] )

Regula can be translate to ''rule''

Even in some latin and non-latin langauges regula, for example, is a form of the verb that translates to regulate. I think regula can also be an adjective given to someone bossy.

To be honest, i think it fits regula, I, for some reason found him a bit cocky and bossy.

and again, its way of behaving (well, 1.x nael didn't gave it away either) but due to is dialogs and voice acting (ive heard it in game in both english and japanese the Aethereocmical...... facilty fight and sounds male to me.)