Interesting discussion.
I think the major issues affecting us are down to the physical output versus the injuries versus the expectations equalling pressure that a young side has not got the experience to deal with. And let's face it, we have three seniors who know what that pressure really is. Romero, Sonny, Davies. Maddison is a senior, but he has never been part of a 'clutch' side that wins massive games and knows perpetual pressure either through a tournament or expectation. It is why the first three are so important IMO. I think we have missed Davies experience personally, Sonny has sadly been flogged within an inch of his game-life, and Romero has either been injured or somewhat mentally absent for much of the season. I think when those pillars aren't firing smoothly, the 'rough idle' spreads and players start to misplace simple passes/make irrational decisions.
In that regard, Archie Gray is even more phenomenal, and Bergvall's learning curve since November immense. Honestly, they are the two players I personally trust the most (Vic too, Solanke is not far behind and if Deki were fit, him too, followed by Spence). I actually don't trust any of our other players right now, albeit for most of them I believe it is due to temporary attrition of said-injuries/fatigue/expectations.
Regarding Sarr, I think he has really suffered playing alongside inconsistent and (frankly) untrustworthy teammates. Maddison cannot be relied upon, Biss we know about, and Bentancur also appears to have an inabiity to keep it in the pocket when the brick's hitting the fan. So whilst I think Sarr can absolutely be better with continued coaching, I think the main issue in general is that the team is not tight-knit/cohesive enough and has too many current untrustworthy players.