It's been a factor on top managers being employed later in the game I've brought it up before yet it still persists like many more daft scenarios.
Guardiola leaves City for Juventus and then to Liverpool on wages far lower than what he's on at the start of the game, it happens with Klopp, Zidane etc. But I see it happens with players too.
FM has put the Mbappe free transfer to Real Madrid yet he earns £275,000 pw which is less than the wage £375,000 pw Haarland earns from an £118,000,000 transfer to City. A free transfer for a player of Mbappes value would surely command at least £500,000 as PSG pay Messi £850,000 pw, Real are paying Benzema more and the skint Barca pay Griezmann £300,000.