Late Roman Unit Sizes

[Flavivs Aetivs]

According to wikipedia:

"The rank continued in use in later ages: Greek writers wrote of "chiliarchs" when referring to the Roman legionary tribunes, and in the Byzantine army, the title was used as an alternative to that of the droungarios and the taxiarches."

Could this mean that the four Chiliarcae were 4 Legionary Tribunes, commanding 6 units?

This would make sense if we saw 4 legionary units of 800 and two cavalry vexillationes of possibly 200. This would make sense when considering the Beatty (Panopolis) Papyrii, which lists the Cavalry part of II Traiana at 160 men.