First it’s the minor leagues, and most of his experience is in the lower levels, it’s not even close to the level of pitching he’d see in Milwaukee.
More importantly smaller humans don’t have the same extension and mass as taller players do, and the pitch plane mismatch is more significant. Thus, the margin for error is that much smaller and he’ll need near perfect mechanics.
Can a small player hit for power in the major leagues, sure. Is it likely, no.
They were always going to trade Peralta, I just would've preferred someone who’s ready to play now at a position of need.