A while ago (Yeaks, several years ago) while working on my DC generator controller the question came up: What was the reason for so many High-Drive type alternators, esp given that from an electronics stand-point is is so much simpler to design around low-drive (being able to use NPN trans or N-Channel FETs). Today I think I might have come up with a reason: Flyback
With high-drive config the flyback snubber directs the current into GND. While with a low-drive deployment, that energy is routed into the + side of the battery - creating more line noise.
Seem plausible?