This is where I depart from your reasoning.
The fact that Pogba is paid at a level appropriate to his talent is not a reason Andreas Pereira should be on 50k a week.
Salaries at United should not be self-referential. I doubt Rhian Brewster's compensation was comparable to Mo Salah's, that's probably why Liverpool found it easy to shift him. By comparison, because we overvalue and overpay, United end up hawking players around for years until they either give them away e.g., Rojo or virtually give them away e.g., Darmian.
Market value should dictate what players are paid at United. Were I FD at United, I would say to any player telling me they want a bigger contract cos Rashford's on big money: 'Okay show me your 21 goals last season then.' Do we really think the likes of Brandon Williams would not sign a new deal at United if they were offered less money than they are on? No chance. If any squad player at United is convinced they can get better terms elsewhere then, by all means, they should try and report back how it goes.
On the subject of Pogba, his market value is extremely high. Given not only his footballing talent but also his commercial value, given his popularity with particular target demographics for advertisers. I would not have any issue with him being paid very, very large amounts of money.
But its gotta be Zidanes and Pavons. It cannot be Pavons paid like Zidanes. That's just throwing good money after bad.