I think the thing I would look at also is this... How does the guy play defense? Because if he's not improving your defense then I wouldn't want 90-20-20 or 20-90-90.
And what deanod says about the variables is absolutely correct. Things that I am only starting to understand come into play, like push/pull tendency.
For instance, a guy with a push/pull of 5 can go yard more often with 70 power than a guy with 90 power and a push/pull of 50. Also the side of the plate they bat from is huge. Let me give you a quick example...
Contact 90 Power 20 LH 50 RH 40 Eye 75
This guy is automatically going to hit better against left handers, correct? Nope. Not at all. And there are a dozen reasons why that might not be true. If he's a speedy switch hitter he's gonna get more infield and bunt singles when he bats left handed. If he's left handed then he may actually have a better average against righties than lefties. Why? Because every time he faces a left handed pitcher he is going against that pitcher's higher split which might average 65. And when he faces right handed pitchers he is normally facing that pitcher's lower split which might average 55. Throw in push pull tendencies, bunting, speed, ballpark and you have enough data to make your head want to explode sometimes.
So like deanod said, to give you a ballpark number is nearly impossible and not at all fair. You gotta figure it out yourself.
But put either one of your guys (90-20-20 or 20-90-90) in Santa Fe and they can hit .300 with 30 BOMBS.