For now it seems that at least some of the excellent 3D stock assets have been made with purely static use in mind.
Take the otherwise excellent 'Praying Mantis' model from the Stock Collection; there are 2 Groups visible in Stager which have been made to facilitate mapping and shading, not articulation. We cannot really 'pose' the model other than by global TRS.
I 'need' to be able to Rig models for deformation and animation - the leg segments must have proper rotation points so that one can turn the head, make the limbs work - to make the model 'alive' so to speak,
Fully aware that Stager is not an animation environment. The point is that by default, the models are not set-up with hierarchial grouping and articulation possibilities down the line.
This is too bad.
It is obvious that animation rigging is done 'elsewhere' in the workflow - Blender, Maya etc.
Likewise it is obvious that if we had default granularity @ the joint level - ie. rotation - the Stock Models would be a much better value.
So; complete hierarchial grouping of model with @ least basic rotations built in.