Since the battery grounds to the gearbox and my regulator case grounds to the timing chest (it's bolt into the engine block), I don't think this ground path is "split."
I have a separate case ground from regulator to the frame, and the ground strap from the timing chest to the frame, AND the factory black ground wire that goes through the loom to the (junction block for) the negative battery terminal.
Because I've grounded the horns and headlights to the frame, I wanted that point grounded back to the timing chest/engine case.
Of course, that's probably way over the top, but it *evolved * that way. In my way of thinking, the frame is the redundant, not primary, ground path.