Rashford has had his head turned by fame and he's on huge wages, but he's still only 26.
He'd score starting on the left for us and he'd be tricky to ignore whenever in form. What I see in him is an approval-seeking personality who's starved of approval at a rustbucket club. So I think he'd arrive eager to toe the Arteta line, and that would continue as long as the validation of selection was there and success on the way, especially given the cultish atmosphere we've fostered.
Any contrary twists in the tale would likely lead to the resentment and attitude problems seen at United.
Potentially we win a title adding Rashford to the XI, but it'd be a huge gamble for these reasons, so why not sign a hugely expensive game-changer with fewer pretensions and downsides?