Zodiac and Late Roman Army Organisation

[Robert Vermaat]

Robert Vermaat wrote: Seniores are always in another unit from the iuniores (it's not even clear what exactly they represent). Exculcatores are never a specialism within one unit. If they were, we'd need at least several soldiers from one unit describing themselves as either an exculcator, or a lanciarius, or what have you. They don't. We have a number of specialisms, and Vegetius, the Perge inscription and Lydus mention a great deal of them, but exculcatores are not among them.
I found the term seniores exculcatores in the ND taken from the internet so I thought it must have been a separate unit. Now I am really confused about the ND.

You did not find 'seniores exculcatores', you found 'exculcatores seniores'. As the exculcatores iuniores, they are part of the auxilia palatina, commanded by the Magister Peditum. The may hark back to one single unit of that name, later split into a seniores as well as a iniuores unit at some date, as happened with quite a number of units.

Do you know which year Zosimus is relating to when he cites the 6000 men is organised into five regiments?

Sadly, no. The publishing date of Zosimus is somewhere in the 5th century, but we don't know exactly when. He may have lived under Anastasios but his work does not continue beyond the year 410.