Like the other units stationed on Tukayyid there likely were a handful of other survivors but nowhere enough to form anything but an adhoc command with many of the survivors splitting up into smaller group to limit the Blakists' ability to target them with their WarShips. I don't believe that it is ever stated when exactly Redburn was captured by the Blakists (whether in the initial attack or in subsequent fighting). After the unit was shattered in the Blakists' initial attack, the unit was never reformed. By the time the Ghost Bears reached Tukayyid, the Star League had disbanded and all the Great Houses were fighting for their survival so there was nobody around willing/able to provide the needed support to reform a non-House unit.
