Has Dybala shown he can lead a line by himself though? I know Juve likes to play with 2 upfront, and Jose has always shown a penchant for a single striker upfront. Not disagreeing with you, I think he's magical, but I have my doubts if he can lead the line by himself, and if he needs that second forward alongside him then the issue is like with Griezz, they'd both have to kick PP out for them to truly shine here.
Dybala has the skillset to play as a False. 9 through the center, yes, but he can't be expected to lead the line for a Mourinho team since he has historically relied on more prototypical #9s. However, the suggestion was more as a wide forward on the right of a three - for which Dybala has the requisite skillset (like Neymar - who went wide because he has the skillset for it, and now thrives in that role, or Hazard - who is nominally a #10 at his best but super effective through the left). The difference in dribbling from them to Dybala isn't that great, especially in comparison with Griezmann.
The problem with Griezmann as a wide forward is that his game is not that much about consistently dribbling with purpose and beating people, but more about intelligent movement in or around the box (evidenced by something like 2.3 successful dribbles per Champions League game for Dybala vs 0.3 for Griezmann, or 2.2 successful dribbles per Serie A game for Dybala vs 0.8 successful dribbles per La Liga game for Griezmann), and that might be a problem for United because we already lack consistently good dribblers outside of Martial and Mkhitaryan.
That becomes an even bigger problem with someone like Zlatan at 9 because at his age, he has a propensity to slow things down while orchestrating the attack - which allows the opposition defense to reorganize - giving a 'park the bus' feeling. You always need a good mix between movement based players and dribblers to avid predictability (like Robben and Ribéry with Müller at his peak under Heynckes, and it's no coincidence that Costa and Coman has a big effect on Bayern last season under Guardiola because they could stretch the field in wider areas - allowing Müller and Lewandowski to exploit spaces in more central areas). Now, Dybala isn't in Costa's realm as a dribbler or speedster, but he is definitely comparable to someone like Coutinho in that department - who is deadly on the left of Liverpool's front three as a dribbling and creative presence.
With Dybala in the fold, our team will be perfectly set up to replicate something like this:
Martial can stretch the central defense vertically and slip through the centerbacks like Aubameyang (though he isn't that level of consistently lethal scorer, yet).
Mkhitaryan reprises his Dortmund role.
Dybala could act like our version of Reus (prefers to play at 10 - like at Mönchengladbach, but also has the overall dribbling + creative skillset to play wide).
Pogba as the left sided AM/CM hybrid.
Herrera box-to-box. Maybe upgrade to Saúl in the future.
And a holding midfielder who can pass well and also screen the back 4 (à la Busquets, Alonso, Motta, Carrick, Weigl).
That attack was incredibly dynamic and potent from all angles (82 goals in 34 Bundesliga matches, vs 80 goals in 34 Bundesliga matches for Pep's Bayern). And United could add more power and dynamism to a similar formula with Pogba in midfield. What worries me with Griezmann at 10 is that he will restrict Pogba when the latter forced to play as a pivot in a 2 instead of a transitional attacking/central midfielder:
An interesting part of Juventus’ midfield game is their asymmetrical shape, as Khedira often drops in the right half-space to support Marchisio in build-up. Playing to Marchisio’s right, Khedira acts at the level we saw him playing for Real Madrid. He’s currently one of the best central midfielders in Europe. When he drops back, Pogba takes a higher position. With Pogba inclined to drive forward, Khedira’s movement balances the team’s structure.
Under Allegri, the same Pogba has shown his versatility by dropping deep towards the centre backs in the build-up or floating through the left half-space to receive the ball with the team in possession of the ball. Pogba often does contribute to their build-up by dropping deep alongside Marchisio and by creating a passing lane between him and the centre-backs in the way to receive the ball when Marchisio is covered by the opponents. His level of play strongly increased under Allegri’s tutelage. Pogba became a more complete player, adding playmaking abilities to his resume. He scored seven goals this season, creating 50 chances and 12 assists.
http://spielverlagerung.com/2016/05/11/juventus-controlled-offense/
This is perfect for United because Herrera can play like Khedira and drop back with the #6 when Pogba goes on rampage.
The alternative would be Griezmann out wide (where he won't be
that effective, especially with a standard Mourinho 9, IMO). Could be wrong, of course, that goes with saying - Griezmann could very well come in and set the league alight, it's just that we'll have to be very careful about the individual pieces and overall balance, especially when we're paying loads of money (world record level) for players that thrived in systems where the balance in terms of what they needed was delightful.