We don't need to find a player of his skill set, which is the whole point of letting him go. Like you said, Pogba is unique player, what makes him very difficult to accommodate (especially in current United team).
The way I see it, we should sell Pogba, and buy two players:
- wide forward who will contribute to assists and goals (in numbers: goal contribution every 316mins, I'd expect Sancho to beat that easily)
- an all-rounded Central Midfielder, focused more on defensive side of game (not necessarily a pure DM)
The thing is, we need both of those players anyway (whether Pogba stays or not).
Even in the setup you presented, you put Pogba on left wing. At this point it seems a bit forced to keep him here.
Not punish him, but if he doesn't want to be here, then it makes no sense to build the team around him. Which as many suggested is the only way to "unleash" Pogba.
The second obvious answer is the money. The third important aspect is the club image.
Don't people feel giving him another year, finding a perfect midfield partner, etc is a bit forced at this point? Bruno came in and it just clicked. Cavani at 67 looks like a perfect fit. Shaw improved massively, feckin Scott McTominay scored more goals than Pogba last season. And what has Pogba done in the last few years here, that suggests he'll finally fulfill his potential, which is arguably much higher than all those players I mentioned? It just doesn't seem justified at this point.