Use of Leather as armor

[Flavivs Aetivs]

I still will argue against leather Armor, there were around 30 Fabricae in the late empire, probably with a thousand workers each. Around 5-10 of these were for making metal cuirasses, which could supply easily the late roman army (200-400 thousand men depending on your source). Furthermore, it is well known that equipment was "hand-me-down" as well, which is probably one of the reasons why segmentata (it had to be custom fitted usually, otherwise it was extremly uncomfortorable).