What our structure is for creating cast alu clutch/transmission housing is like an
assy with skeleton model with the inheritance of your top model.
the assy contains a number of sub skeletons to control pull directions in the die.
the assy contains a standalone cast model that is made with copy geom and solidifies from the sub skeletons. then a standalone part with a copy geom of the cast and the inheritance from the main skeleton that also contains machining curves.
inh from top model
geom needed for sharing in multiple sub skel and machining features