My profile fails to mention the 20 years I lived in Upstate New York. Winter driving is worse here anyway... more freeze/thaw cycles means more ice. And we don't have decent snowplows.
"even with equal drivers, a fwd would have an advantage on rwd in the elements" means you don't know how to properly drive a RWD car in winter, or you wouldn't say that. FWD is better in snow for inexperienced drivers for the same reasons FWD is better in other conditions for inexperienced drivers.