He's half the player on the right side of the pitch.
Rashford's goalscoring is his most valuable quality, and that's currently being blunted by his starting position consistently forcing him onto his wrong foot.
A lot has been said about his recent spate of offsides, but I think it's a direct consequence of his lack of confidence about playing from the rightwing. During the Villa game, he had several goal attempts where he looked awkward firing in shots from his weaker side. I believe that's what's making Rashford extra desperate to get an extra yard of space by starting his runs extra early.
I reckon if you put Rashford back on the left, he'd be more comfortable about holding his runs for the pass. As an added bonus, he'd also be able to put more power and accuracy into his strikes.
Whilst I understand the logic of putting Pogba on the left, Ole has to ask himself whether the gain for Pogba is worth more than loss for Rashford. I don't think it is. Over the two games Pogba has played on the left, he's had a total of 0 shots on target, 2 shots off target and 2 shots blocked. Swapping Rashford and Pogba around wouldn't do either any harm, imo. And at the very least, it'll likely do Rashford some good.
The Pogba-left-Rashford-right hypothesis is being disproven by the results. Put Rashford back on the left.