"Lean" toward Whitaker? Whitaker would be a huge favorite Mark. I will slide him over into my "Enormously underrated by Mark" folder mate.
Nelson, on form, was an amazing brilliant pressure fighter. He just had a pretty bad tendancy to sleep walk through fights, meandering on the front-foot with a high guard up and not throwing. But when he's 'on', he's on fire. That's a pretty good style match up for Sanchez, who'd definitely struggle more with the Gomez/Fenech II style Nelson implemented, with movement, a heavy jab and counters. As for Sanchez vs Whitaker, there's no way Sanchez wins. Or even does particularly well. Whitaker is a bigger man, a better fighter and an abysmal style for Sanchez. It looks like a higher class verison of Mayweather-Marquez.