Donnie Baseball was THE reason, why I liked the Yankees when I was a kid.
Now as an adult, I'm not that big of a fan.
But to answer your question, this is my first year playing fantasy baseball, but I'm sure that he was a first rounder. I mean who else during that era had his combination of power and average? If I recall back then, you either hit for average (Wade Boggs), or hit homers, but K a lot (Strawberry, Pete Incavilgia, etc). Mattingly did both.
Be interesting if anyone here went back that far.