Personally I think we were struggling to work it out because of the lack of width, we were too slow in the build-up due to Laporte's injury but the main issue was because we were too narrow with Sterling cutting in from the left and Mahrez doing the same in the right, in my opinion. Sane, I think would have made the difference, even just as a different option, he creates fear in opponents that make them change tactics just to counter him.I think thats true, but teams had set us a puzzle we were stumbling to work out by sitting around the a packed area we were finding it difficult to play through and the refusal to come out meant they didn’t tire as much. While we had extra space on the wings the make up of our team ,short, left if difficult to cross.
It’s so long since I saw us play now I have a memory of later games with Mendy and giving KDB more freedom and an improved Mahrez we had worked it out but it’s all a bit hazy now, but have no doubt Pep will have come up with a plan for the games left and next season Sane or no Sane, like for like replacement or not.
Liverpool manage to create the width with their fullbacks but I don't think it'll be long before someone works out a plan. A few have managed it this season but old United style first goal assistance (e.g. fortunate decision or fortunate goalkeeping errors) have given them a helping hand on most of those occasions, that fortune can't last forever.
I hope you're right with the last bit, pretty confident you will be. We're lucky to have him.