Late Roman Unit Sizes

[ValentinianVictrix]

Germanic tribal identity was fluid, it's possible many still existed as Cantons but aren't mentioned because they were under a greater identity like Salii or Iuthungi

It's thought that the Lemovii went on to form the Rugii of Eugippiu, for example.

EDIT: It's clear that a number of units named after tribes were not recruited from them. The Heruli are a good example, being stationed in Gaul in the 4th century, while the Heruli were at that time bordering the Black Sea East of the Dniester.

I'd be very careful with stating as bald fact that the Auxilia Palatina Heruli unit had not been recruited from the Heruls. They did enter Roman territory during the 3rd Century AD and it may well be the fact that a part of that tribe stayed north of the Danube in the area near to the Taifali tribe as the Taifali also were recruited into an Equites unit as well as a Auxilia unit.