A feature to play as IRL managers would be great, so I can start a save without having to have managers magically sacked. Would be great to get immersed in a save, such as winning the Scudetto as Jose Mourinho with Roma, or winning the UCL as Pep Guardiola. Maybe playing as a recently-sacked manager like Steven Gerrard and going on a redemption journey
This feature, of course, may come with some legal issues. This means that features such as additional comments in press conferences should be disabled, which isn't a very popular feature anyway.
Player-controlled IRL managers could also have their names be highlighted a certain colour in-game, to prevent any confusion or issues from arising.