*This seems like a good idea, but in fumbling around, I discovered something that works. . . one can select a figure, and choose "Set Figure Parent" -- I'd never found my way to this bit of menu before. Poser is oddly "modal" with respect to geometries. Some geometries are "figures" some are "props" and so on. In the case of figures, you have to pick the figure, be sure "Body" is the part selected, and then "Set Figure Parent" -- which I do to the Tawhak hip.

This seems to work OK, so far . . .

Excellent!  I'll give it a try.  Kind of sounds like Lightwave when working with layers...