So asking a player to focus a little time on a new position won't hurt them, but it will help them? I mean prospect development is kind of a zero sum game, if that time is beneficial then that means you're taking away from their development. Again, there is a reason why teams DON'T do what you're proposing.
Why don't pitchers take more batting practice in the minors?
And to reiterate Users point I think you're underestimating how crucial prospect development is. There is a huge mental side to the game, and filling a guys head with a bunch of scenarios of how he's supposed to play at one position but then have him go out and play another (even if it's a few minutes every day) can really screw a guy up in the head.
If Moncada is going to move off of 2B you're likely not going to see it until he reaches AAA. And for the record, I never once said Pedey would switch positions so that was either a straw man argument or you didn't understand my point on the last page.
Again, and I can't stress this enough. You CAN NOT look at prospect development from the top down, you take a bottoms up approach. You let a guy develop where he plays and where he has the most value. When he is MLB ready then you can either trade him if he's blocked, or if it is in the best interest of the team you can move him. But even then at the MLB level it can screw a guy up e.g. JBJ.