Let me set this question up a bit to establish why you would even WANT to do this.
Say I port a Genesis 8 female from DAZ to Blender using diffeo. Now in DAZ I pose the model and use Sagan to port the posed models. The sagan alembic exporter is now supposed to export the geometry, UVs and faces of the mesh by itself, using the diffeo in the host blender file to get it's materials. Sagan reliably exports geometry, UVs and faces. However sometimes it screws up on the materials and puts them in the wrong places.
My idea was to simply link the materials manually- but then I found another issue. Apparently, something in the albemic system organizes the materials on a mesh by name. This doesn't appear to cause any problems on the surface, but if you want to just link the materials say- between the alembic model and the model imported through diffeomorphic- since they're in different orders- the alembic model now look like trash as the materials are assigned to the wrong places.
So I experimented. What if I took "arms" and manually put it at the top of the list? Lo and behold- the arms material can now link properly.
So then- is there a way to alphabetize the materials on a mesh? There doesn't seem to be a reason not to and if you had enough you might want to do so- how would you?
BTW, anyone working with these two programs- this looks like it might be a work around to make them work properly.