I havent read it all cuz of work, but from a quick peek, i still dont understand the khedira case.
He talks about the regista role which would be the 4, ok pjanic check...
Currently we have no number 10 on midfield. According to what he describes, a bernardeschi type would suit his needs there... as he is talking about someone who could push forward, find ways to set up the forwards and have a good shoot. But he is not using berna there.
The last spot is the 8... which supposedly is khedira. From what i see, framewise khedira has what he wants, but on the field he is noweher near the 8 he is talking about. The only thing khedira does is win headers... but he is not someone who will create numerical advantages with dribbles nor soemoen who would impose his physical presence and cover the 4 and 10. In fact, he is the contrary of that. He plays like a offensive midfielder but without playin like one.
In allegris set up, what i see is more of pjanic as the 4, matuidi as the 8 and khedira as the offensive mid. Imo khedira is the one who doesnt fit the 8 nor the 10 role who allegri describes.
For that reaSon, i feel that if marchisio is fit, we should try him more alongside matuidi and pjanic, as someone who would help distribute the ball and balance the midfield, while pjanic carries the major burden of making the play and matuidi the physical player.
If not, we can try a double physical mid with matuidi and sturaro flanking pjanic... just like we did vs udinese but pjanic instead or marchisio.
All this proposed combinations would suffice for me, but all this requires to bench khedira.
To finish this post.... I think that the midfield allegri would really love to try in a 433 would be:
PJanic as the regista number 4
POgba as the b2B dynamo, physical, pusher and with header prowess, the number 8
And someone like bernardeschi as the creative outlet who would 1v1 and shoot from afar or assist.
Imo taht would be his dream midfield according to his essay