This very circumstance serves to explain why Caesar made no attempt to re-establish the Roman burgess-cavalry.

The levy was better arranged, the time of service was regulated and abridged; otherwise matters remained on the footing that the infantry of the line were raised chiefly from the lower orders of the Roman burgesses, the cavalry and the light infantry from the subjects.

That nothing was done for the reorganization of the fleet, is surprising.
Foreign Mercenaries Adjutants of the Legion It was an innovation--hazardous beyond doubt even in the view of its author--to which the untrustworthy character of the cavalry furnished by the subjects compelled him,( 34) that Caesar for the first time deviated from the old Roman system of never fighting with mercenaries, and incorporated in the cavalry hired foreigners, especially Germans.

Another innovation was the appointment of adjutants of the legion (-legati legionis-).

Hitherto the military tribunes, nominated partly by the burgesses, partly by the governor concerned, had led the legions in such a way that six of them were placed over each legion, and the command alternated among these; a single commandant of the legion was appointed by the general only as a temporary and extraordinary measure.