Gallienus\' Central Cavalry Reserve

[Artorius1960]

When Gallienus created the central cavalry reserve in the 3rd century, did he expand the cavalry arm or merely consolidate it; for example, by drawing on the legionary cavalry alae and forming a larger body from them?

I'm curious about opinions on how the creation of the reserve affected or strained the resources of the empire. I assume that if Gallienus created whole new cavalry units, there would be a need for arming and equipping them that would put the fabricae working overtime. On the other hand, a consolidation of the legionary alae, would simply be a reorganization of existing units and require very little from the fabricae.

If the expansion of the cavalry involved recruiting mounted troops from within the empire (indiginae) or from outside (such as Sarmatians), would these troops fight in their traditional style using their own traditional weapons or be re-equipped from imperial resources?

Mounted troops like Equites Mauri, appear to have fought in traditional style, as would the Sarmatians. But would other types of indigenous mounted troops, such as Equites Sagittarii, be equipped by the state?