The discussion is why can some players who are a 10 or an inside forward able to play as 8’s (Bernardo Sliva, Havertz, McAllister, De Bruyne, Foden, Bellingham) examples off the top of my head (I know McAllister is playing 6 atm) and others can’t? How much of it is tactically or position inflexibility or the manager not setting up the team properly.
And yes I am wandering my Mount or Bruno can’t play as double 8’s like the rest mentioned can.
Well, I think it depends on the personnel in the team.
For example, KDB and Foden are playing as 10s/8s because they have a solid defensive structure in place in the form of Rodri and their situational back three.
However, certain teams that can be vulnerable in transition would not be able to do that. I think a good example is United as you’ve pointed out. At least, they aren’t in a good position right now until Varane, Martinez, and Amrabat return to full fitness.
But I am still open to the possibility that certain managers just decide not to or they think that a player cannot play that position.