Not a stupid question! I didn't know Phil did outboard bearings. (I don't have any two-piece cranks, so haven't needed to keep up on what's available.) Based on what I'm reading elsewhere online, Phil makes a French-threaded stainless steel outboard bearing cup and you should be able to make it work with a Shimano Hollowtech II crankset. I'd suggest not taking my word for it and contacting Phil Wood for details.