Isn't it possible that a couple of months in the minors would be good for him?
Possible, but for the heck of it, there's an argument it isn't.
Stuff-wise, I don't think there is much dispute that he is major-league ready. The issues seem to be with men on - rushing to the plate, holding, etc... Odds are, he can work on that a bit better against hitters who can actually challenge him and even get on.
You want to limit his innings, which would be easier in the minors, but not impossible at the majors
Where are the training facilities better? Probably at Nats Park.
Who are the top coaches in the system? Dang good question, but probably at MLB where there are more of them.
Where would there be less moving around? A start for Potomac in the opener, a start for Harrisburg at Bowie, then Nats Park for the Brewers would let him stay in one spot.
Where is the weather better before June? Washington beats Syracuse and Harrisburg until mid may or so.
I'm not convinced, but if you threw out the money angle, it is not open and shut thatthe minors are better for his development.