That's some Team Sky logic ;) It doesn't matter when you have to ride your sponsor's bike.
Example: Pogacar's Colnago is decidedly not aero; Cavendish's Wilier ain't the best sprinter bike.
But they're all competitive, because like I said, the role the frame plays in the overall "system" is negligible. It's marketing. The aero gains on the new Madone are entirely in the handlebar, and are erased if you add a rider to the bike.
If we're talking about emotors, they need to be compatible with the drivetrain, regardless of frame.