As always Blakey an enjoyable summary by you - whilst I might not always agree I do give you huge props for always producing a considered review, and doing it lightning fast.
As usual, it's getting bit groundhog day now, I don't agree with your summation of the midfield, or you just taking six players in isolation from the remaining five ... that's not how the game is played.
Look at the whole team set-up -
An experienced keeper - we have two now so that's a given
Two centre backs who whilst not the fastest on the planet are rock solid under aerial attack and who do have the odd raking long pass in their locker.
Two fullback (and this is the big change in 2020) who are primarily attacking players with the ability to both score and assist but who also have the ability and speed to be competent defenders. Doherty and Reguilon are a big step up from Davies and Serge.
A central midfield player who will break up opposition possession and can distribute the ball with ease - PEH again a step-up from Winks.
Two other mobile midfield players who can drop back to cover their fullback, can battle one on one with their opposite midfield number, and who offer an attacking threat - these are your >100m players
Three strikers/wide forwards not only capable of scoring but also of providing assists, pressing, and when needed covering an opposing fullback's runs - these are the games glamour guys, we have three very good ones.
So why Sissoko over Ndombele + LoCelso? is he a better player than either of them? that's not even a debate clearly ability wise he isn't, so why? Well it's horses for courses, right now Mourinho very obviously believes a 31 year old Sissoko has the experience, and more importantly the 90 minutes fitness levels, to do a better job alongside PEH and one from Ndombele/LoCelso, than playing both of them together would offer.
As those two gain fitness and EPL experience then no doubt an ageing Sissoko will be phased out, who knows maybe Winks or Dele can also step up their game, maybe in January we trade for another quality midfield all rounder ... either way a 32 year old Sissoko won't be a fixture.
That said right now Sissoko is the man, it's Sissoko who covers when our FB's range forward, it's Sissoko who allows PEH to press the opposing midfield, it's Sissoko who's still going after 90 minutes ... he is the man, praise is due.
That won't last, indeed yesterday he was the one first substituted for an extra striker - so the writing is on the wall for our 31 year old 'legend' - just maybe not quite yet.