\"Celtic\" military technology and the Romans

[Renatus]

Ammianus Book 16 ch. 10 -8

"thoracum muniti tegminibus et limbis ferreis cincti" is usually translated as "protection of iron breast-plates, and girdled with belts of iron". However, limbis is not a usual word for 'belt' in Latin, and literally means "piping" or "border/edge". Could be the description of some sort of combination armour for the torso.

However, limbus has a secondary meaning of 'belt, band or girdle', so the implication of the passage is that the body of the clibanarius was protected by a combination of solid breastplate and iron bands, perhaps allowing an element of flexibility.

We know that they wore both kinds of armour but I can't think of anything to indicate that both were worn at the same time.

Is your objection to the suggestion that one form of armour was worn beneath another? Julian's description of Constantius' heavy cavalry suggests that different types of armour protected different parts of the body (Oration I, Panegyric of Constantius, 37D), which seems entirely sensible.