All 5 key "blue" ratings (contact, power, VsL, VsR, eye) factor into determining hitting prowess. You'll want the other 3 ratings to be 75-80 or so, or at least to average that, if he's going to be a guy who makes a living off his bat (as opposed to some combination of his bat and his glove or legs).
Also, because many owners don't pay huge attention to the minors in HBD, minor league stats don't translate to the majors nearly as cleanly as they do in real life. Basically, they don't translate at all in HBD.