Not going to like this answer on this board but.....
Rosters above 40 are nothing more than enrollment tools for the college. Enroll here and come be on the baseball team a while. That's it in plain language.
Many D2's are notorious for this. My area Juco's are running 90+ players and this is before the D1 dropdowns come calling after December. Two specific D2's are running at 90 and 110 players respectively. Most midlevel D1 rosters I see for Fall or have kept up with are 45 to 50.
Why? One simple reason. This is a byproduct of the current money ball system of showcases. Many smaller Colleges are using sports of all kinds to boost or entice enrollment numbers. And right now there is no shortage of willing payers lining up for their shot at playing college ball, even if that means 3 or 4 teams worth of players in the program that will never see the field.
Best of luck.