I don't disagree with any of that.
Just wondering what I would do if I had an ironclad guarantee that Sancho would turn down anyone else but us next summer.
Our squad needs quality more than depth, imo, even right now where it is a squad that could be much better than it is. Lesser players orbit the quality ones and are reduced to basic, dutiful tasks within a remit they can actually handle - make them try and play an expansive game because they've got to be rounded players as we've got no one who can alleviate the pressure, and you see a lot of them [squaddies] become useless and non viable options.
A few examples in our squad currently: Mata, Jones and Lingard. Ask any of them to play a game with full responsibility and no hand-holding and none of them are capable. Put Jones in as a dogged man-marker with a simple job brief, and he can do that job against almost anyone you can think of - suddenly, he's gone from useless to a very useful squad member with a distinct skill that nobody else has; give Mata the brief of linking play and keeping chain passes going or being the free man for a top quality forward, and you've got someone who won't be the liability he currently is who is slow, weak and has no stamina which is exposed almost every time he sets foot on the pitch. Lingard wouldn't look nearly as bad as he currently does if the opposition had no time to focus on him because a much bigger fish is lurking who needs a double or triple team.
The right kind of bona fide star also eases the passage into top level football for academy graduates too, so even if you don't use the likes of the above, you can redistribute their minutes to players earmarked as having a future here.
With regards to Sancho, he's not on the level of the above yet, but again he brings a lot of things the table that can aid lesser lights whilst also elevating the first team. Squaddies are ten a penny; can even be had in the winter window - I think the names being bandied about in here are a bit fanciful because their cost isn't associative of bench warmers unless you're an oil club, so re-frame the question with actual squaddies vis-a-vis a superstar and the answer is a no brainer. Now, if the question is/was:
strengthen the 1st xi or chose a superstar, then the answer becomes harder and understandable whichever is opted for.