HTown, I (strongly) agree with you that Donaldson is out of position.
Coaches problem is that he can't move him back until he has a better option at RT. And TBH, the real problem is LT. Because by far the best lineup is St Louis at RT, Donaldson at RG, Gauthier at Center, Boulware/Mahoney at LG and Player X at LT.
But who is this mythical Player X who can play either LT (ideal) or RT (second choice)? So far, Jones failed at it, Brown failed at it before getting injured, Herbert and Hillery proved to be not yet ready for whatever reason. ...Right now, the guys on the depth chart running with the 2s are true freshmen Scaife and Campbell. Until they or one of the others can play well enough not to get our QB knocked out of the game, coach is kind of stuck.