Roman Legion in late Antiquity

[Flavivs Aetivs]

You may have mis-read. A century likely numbered between 60-100 men in the 4th century, depending on variable factors (understrength, etc). A legion varied. For Limitanei it is possible it numberd at 3000. For comitatenses it is possible it numbered at 800-1200, and for Legio Palatinae it is possible it numbered at around 800-1200.

A cohort probably still existed in some units, and didn't in others. Many Palatinae and Limitanei were not organized into Legions, and were cohort sized units. Overall it is believed that the 800-1200 man Legion was divided either directly into Centuries, or into maniple-sized units and then into centuries (The ducenarius is still debatable).