I think Wagner has poisoned the Armed Contractor concept for a whole long time.
I’m more thinking of readiness and training levels (and equipment levels).
Joining the PRes every one needs to do recruit/basic/basic trade
Then one can stream to;
A) a ready reserve unit that is part of a larger regular entity, they have more training days more requirements, and unlimited class B or C with the regular parent.
B) a reserve unit that is more of a territorial defense force - limited Class A and B opportunity
As well as life changes members can switch between them (as long as not on class B or C at the time) and meet the requirements of the entity they are transferring into.
The Ready Reserve would pick up a lot of student and seasonal workers - while the Territorial entities would generally be older with fixed careers with less room for going soldiering.