If Moutinho does come in (unlikely), I think he'd be replacing and rotating with one of Sandro/Dembele in our starting XI (probably Dembele since Moutinho's not so much of a DM), with one of Sig/Ade/Dempsey in front of them for now, then Holtby + a new no. 9 next season. That's mainly because none of Moutinho, Sandro, or Dembele are capable goalscorers or operate as far as AM.
I'd be pleased with this, as much as I think Dembele is a good footballer. It's just that Dembele's strengths are not Moutinho's strengths, and I think Moutinho's particular qualities would suit our team more. While Dembele's a wonderful tackler, dribbler, and runner, he (and our other players) tend to hang on to the ball and run with it, or take an extra touch to control it/look for passes, which slows down our play and in particular our counters. He can certainly contribute to attack, but his passing vision is not really that of a playmaker.
Where Moutinho excels is playmaking on the counter. I admit that I've watched him in CL/Euros rather than the portuguese league, which would probably be a better guide to his consistency, but from what I've witnessed, he is superb at circulating the ball quickly, precisely, and with some intelligence and imagination (e.g., he has 3.5 key passes per game this season in the CL, higher than any Spurs player last season or this season). He does not need more than one touch. He has a vision of the whole field before receiving and immediately distributing the pass; in contrast, our players tend to sit on the ball as they look around for runners and teammates in good positions. We are blessed with good dribblers and one-on-oners, the problem is that they do not know when to solo-run with the ball and when to one-touch pass-and-move-it and *build* an attacking play.
The pass is always faster than the man. If we have Moutinho and then Holtby next season, I think we can begin to flow much more quickly, becoming even more lethal on the counter, with more creativity through the middle to alleviate the burden on Bale & Lennon and our reliance on crosses. We can still control the game methodically in midfield, but we'd now have the capacity to speed up the tempo and circulate the ball much more swiftly and intelligently. That would help us create a higher quantity and just as importantly quality of chances, especially against the better sides in the PL whom we cannot rely on individual prowess to beat. A team ethos is now beginning to show in the defensive sense, but we still need more fluency as a team in attack to consistently carve apart teams. Passing brilliance and vision is sine qua non in that regard.
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Plus - keep in mind that under AVB, we want to challenge on all fronts, and both Sandro and Dembele have had fitness issues in the past. We need to rotate better than under Harry last season or we will struggle to maintain momentum in the second half of the season. I know that we may not have funds for both Moutinho and a striker/AM in Jan, but I am hoping we will aggressively sell off our fringe players and at least make some room wage-wise. A striker that AVB likes would not go amiss of course but tbh, the priority for me is in creativity - in creating more and better chances.