The fact that these positions cause such divisiveness among the fan base is proof enough that there are issues.
De Gea might have found a bit of form again after years of generally being off it but he isn't getting any younger and there is no guarantee over Henderson whatsoever.
The fact that the club made Maguire the most expensive central defender in the world is ridiculous to the point of being difficult to believe. There's zero justification why a player that cost such an extortionate fee would also possess this worryingly high propensity for basic errors. It won't be long before any new manager has to seriously consider how to deal with this and doing so isn't going to be easy.
Pogba is a problem for any manager as firstly you don't know whether he is staying or going. Secondly even if he signs a new contract, his best performances since he has been here have been fleeting and therefore it's then the very challenging task of trying to get the best out of him on a consistent basis.
Sancho was meant to finally resolve our right side attacking issues after years of it being plain ignored. Instead he's looked utterly out of his depth since he arrived and people are even now saying he's better on the left where supposedly we're well stocked.
Greenwood may be talented but to say one of the most in the world is a stretch at this point in time. Absolute no certainty he can make the right side his own and even less so the centre forward position.
Ronaldo is one of the true greats but you already have plenty of 'respected' posters and pundits asking whether he'll be more of a hindrance than a help this season. You can understand this perspective at least a little given his age and that a decline at some point is inevitable. Once this happens, again tough decisions have to be made - most likely having to buy a new striker since Cavani isn't any kind of longterm solution either!
Basically this isn't a team or squad, in its current incarnation, capable of winning the league.
You sound a lot like Chelsea fans who were defending Lampard before he was sacked and backing the point he made of Chelsea's team not being ready to compete. Kante was finished, Jorginho was average, Thiago Silva was too old, Edouard Mendy was unknown quantity, Werner/Havertz were bang average etc these were all the points being made by the Lampard in crew who wanted to believe the team was bad when it was never the case and the problem was simply mismanagement. You have to actually be objective and judge the team without this ridiculous mindset that everything around Ole is what's wrong instead of it being him. You simply can't make a serious argument about that almost 3 years in and over £400m spent. Just to counter your points
De Gea has been out of form yes but there's simply no question that an in form De Gea is one of the best GKs in the world he has the quality and mentality to turn his form around and he's been flawless so far he's one player you can trust to maintain good form when he's on it and so what that he's 31? Neuer/Navas are still world class at 35 he could still give us 2/3 solid years which is fine as this team doesn't desperately need a GK for the next decade yet
Being overpriced doesn't mean a player is trash. We overpaid for Maguire but he's improved our defence massively from the Smalling/Jones era, is an EVER present figure at the back which is vital for a position as demanding as a CB and when you compare other big money signings like Coutinho, Griezmann, Ousmane Dembele and even De Ligt(hasn't flopped at Juve but hasn't kicked on from his Ajax days he's been benched a lot for Chiellini and Bonucci) Maguire has come much closer to proving his worth so you're being incredibly and ridiculously harsh. His form for England too where he was in the Euros Team of The Tournament and lead England to the final, getting a goal in the process shows that he may ACTUALLY be a top player believe it or not
Pogba's contract issue is a problem definitely no lie but if he stays we're simply a much better team with him than without him and an in form Pogba makes us title contenders there's no two ways about it cause he's actually a good player. Getting him to play well consistently is something worth looking into but he's done so under Deschamps, Allegri and Conte so there's definitely a way to solve it.
You seem to be making judgement on Sancho based on outside views rather than YOUR OWN views which shows how non objective you are because anyone that's watched Sancho knows that not only did his best season come from the RW but that he'd need time to adapt. Almost all top players that have come to the PL from Germany needed an adjustment period from Son, KDB, Sane, Havertz amongst others so to rule out Sancho who was not only producing a devastating level of productivity in Germany especially in the 19/20 season that was only bettered by Messi statistically but is also just TWENTY ONE years old playing his first season in the PL is absolutely ludicrous. His ability to play on either wing is not the drawback you're trying to point out. Havertz who had a similar problem of adjustment in his first season improved massively when Tuchel came in don't rule out Sancho yet who's a better talent.
Yeah there's no certainty Greenwood's development remains linear but don't you think he's shown enough in his talent and performances to suggest he'll only get better? This isn't a James Wilson situation of an academy player hyped due to being from the academy in terms of talent Mason is up there with Fati, Foden, Vinicius etc as one of the most talented U20 footballers in Europe. He's already one of the highest goalscoring teenagers in PL and Utd history, zero fitness issues and zero attitude issues like Januzaj the odds of him succeeding are not certain but much higher than that of failure
When has doubting Ronaldo EVER worked for anyone? Everytime people say something about him being past his best or a misfit he ALWAYS claps back. 101 goals in 134 Juve games, all time International Top Scorer of men's football, top scorer at the Euros and 4 goals in 4 games at Utd. To put other things into context it stemmed from his time at Juve on myths that he was holding them back from playing progressive football yet Juve have not improved one bit as a team since he left so maybe the problem wasn't him after all? You can't say he's held us back either because our attack is still fluid and the problems we have now are problems that were pre existing even before this season. Lastly Ronaldo is super fit he could very easily play till he's 40, 2/3 years of him is worth more than 5-10 years of other STs if he wins us the big trophies so him being a short term fix shouldn't faze you cause it's Ronaldo the normal rules don't apply to players like him.
) ability to bounce back from misfortune.