Which writer has most harmonies?

[ViscountViktor]

Fleetwood Mac are known for their three part harmonies. Some of my friends who are not into Fleetwood Mac know that.

But which writer incorporates harmonies into their songs the most, and why?

I'd say Stevie, probably because her choruses are long enough for all three to harmonize in.

If one of Lindsey's songs does have a long enough chorus, he might do the harmonies himself, through "vocal engineering."

Christine does have songs with harmonies in, but sometimes her choruses are not harmonized in, and it's unclear why.

Any other thoughts?