Is this a good pre draft ranking?

It's seems pretty accurate in terms of relative rankings (number 1 is better than number 2, etc), but it's a little lite in scope. There are at least 250 players in most draft rankings. Where's Albert Pujols? Where's Tim Lince? Are you uming these will be selected by other teams so that only the 25 named here will be available to you? If so, I don't think all of these players will be available one round at a time. Most of your players in numbers 1 through 6 will almost certainly go in the first round. Most of the players in items 22 through the end will not be drafted in a typical draft. They'll be left unselected.