Well ok, in XSI, this is a trivial matter. These directions are most likely due to tool limitations in the XSI Source Plugin (which sucks a large amount of ____) and less on the process that *should* occur.
You create independent meshes to cover the area of the body/object that the bone will control.
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Then you combine the meshes together into one polygon mesh using a merge tool or whatever, as long as its one piece (again this is for XSI at least, your tool might have more control). Then create an envelope for that giant mesh that attaches to all the bones of the object.
[Insert Pic]
Then weigh each independent piece to the specific bone 100% that you want it to follow. So all verticies for that one block will be pointed 100% to bone X.
[Insert Pic]
This creates literally the same thing you would have when exporting the regular object's weighed mesh, however, it will be independent pieces that represent collision hulls. They move with the bones just like the main mesh, but you have to define it in the QC with $collisionjoints so that the engine knows the mesh is not static.