I said before the Everton game that being able to bring Mahrez, Foden and Alvarez into the line up was just amusing at this point. Not only did they start together and engineer the win, but they all combined to score the 4th yesterday.
The WM formation Pep has shifted to has the benefits of both the 4-2-3-1 (two holding midfielders) and 4-3-3 (two attacking midfielders), all without the drawbacks (sole AM or DM). We also transition into a similar box midfield shape with the ball, but I think their setup appears more secure as it's a fixed box, whilst ours turns into one.
They've also setup that way without compromising on the wide players, but rather playing with a defender short. Regardless, the back three haven't been tested at all and they're suffocating opponents who build out the back, as they have an extra man when pressing.
They're difficult to play through the centre and Walker, Akanji and Ake have been great down the flanks with Stones who can also drop back to support the CB's. It's hard to believe that none of Sane, Vinicius, Saka/Marti, Salah have troubled them over the last month or two.