At 90-degrees crank rotation the crank pin is 1/2 around, but the piston rod is 1/2 way down and 1/2 way over so the piston is more than 1/2 way down the bore at 90-degrees.

Anyhow, I was talking about intake lobe centerline, not lobe separation angle. LSA is usually nearly the same number resulting in an equal split on overlap.