If I added a Sega option, then I'd have to add a Gottlieb option, and it'd be the same as any other poll "vs" thread out there.
I assumed that when William's bought out Bally, that naturally they'd have acquired all of their factory spaces and warehouses and such. I thought that even though Bally and Williams were now one company, that they possibly would've continued to manufacture games in their respective factories--thus having different engineering teams working on them. Evidently not. It looks like everything was consolidated into William's HQ and everything was done from there.