Roman Body Armour by H & J Travis

[Dan Howard]

This is then used as the basis for speculation that 'if mass producing for low-status legionary or auxiliary use, butt joints may have been used to kit out a large number of men quickly.

This makes no sense to me. By the time you get to the stage of actually making links from the wire, the vast majority of work has already been done. The difference in cost and manufacture time between butted and riveted mail is inconsequential until modern mass production technologies can churn out reels of cheap wire. IIRC every sample of Roman mail that has been properly analysed (i.e. xray analysis) has turned out to be riveted, not butted. On top of that, nobody has ever given a sensible argument why the Romans would have bothered with butted mail. The most common threat was from spears and arrows. Butted mail provides no protection against either of these.