Position changes question

For position changes, what should the minimum weight be if I want to move a player to a new position?

Some examples of players that I moved or want to move in my offline dynasty are

MLB to C

QB to CB....He was recruited as an Athlete but placed at QB because at time I thought he would be the QB of future. I was so depleted at CB his FR and Soph years he sees time at CB

HB to OLB

I know it's my offline dynasty and I can do what I want, but I want to try to keep within limits of "realism"

Thanks

For MLB to C I'd say 270+
QB to CB shouldn't matter at all
HB to OLB I'd say 215+

Depends on the school you are at. A smaller school a MLB moving to C could happen when the MLB is 250+, especially with the service academies. Heck the default roster for their starting o-line has 1 guy above 260.