Why?
These plays with Donaldson at 3rd may have ended up the same. Hard hit short hops are tough to judge and Vlad hasnt had enough reps at 3B or any infield position to be able to be in a better position glove and feet to make the play having a better chance to succeed...at the minor league level let alone the Majors. It's something he needs to experience and see first hand and adjust and get better.
That's what this whole year is about