Late Roman Legion size based on the Perge Inscription

[FlaviusB]

the 280-strong regiment I suggested (5 clerici et deputati, 50 Veredarii, 225 Veredarii Alii) can still be divided into 5 56-man Turmae, which is enough for 1 to support each 320-man cohort.

The problem is that the clerici and deputati are probably not the same - they may have been unit priests and medical orderlies, as I think Onur suggests? - and they were not on the army payroll, as they drew no annonae. Putting one supernumerary 'civilian' in the ranks of each turma would seem a bit superfluous, surely?

it could be that a cavalry unit was added to at least some of the Legions (perhaps those whose Equites had not been used by Gallienus to create new Promoti units) to give them some added striking power and improved communications and intelligence-gathering capabilities to offset their smaller size?

I've wondered elsewhere whether this Perge numerus may have been specially constituted as a combined infantry and (light?) cavalry unit, for a particular purpose related to the Isaurian situation; a sort of counter-insurgency force, maybe. However, carving the unit organisation onto a huge tablet suggests they were intended to remain there, and keep that same formation, for some time!

(incidentally, could you edit down the posts you quote in your replies to the specific bits to which you are replying? These threads get awfully long and repetitive otherwise!)

Duly noted regarding the quotes! With regards to the Clerici et Deputati, a way to organize them while accounting for their different positions could be to organize the legion around 'milliary' centuries, that is with 160 men each, commanded by 2 Ordinarii and one Optio with the former corresponding to the centurions commanding the 'prior' and 'posterior' centuries in the maniples. This gives us 6 Clerici et Deputati for one of these centuries, which could be split into 1 Cleric and 5 'Deputies.' The two Tribunes still have 4 each, which could then be divided into 1 Cleric and 3 'Deputies,' while 5 'Deputies' can be assigned to the cavalry unit. As for the cavalry unit itself, it may be that the smaller size of the late Roman cavalry regiments (ie Equites, Comites, Cuneus) allowed for the legions themselves to incorporate a greater amount of cavalry than the 120 Equites Legionis previously available to them.