These systems are so flexible these days it's hard to keep track. Cox highlighted that in possession we switched to a 4-2-4/4-2-1-3 almost, with Tierney moving to LB, AMN pushing up the wing, Auba moving up top and Laca dropping deeper.
I'm with Klaus, I'm not convinced by the back 5, only because it means you have more defensive players than attacking. At the moment it's helping us to get forward with more confidence so it's fine, as Luiz and Arteta said, it's a process. But ideally, and I'm sure Arteta would agree, I'd like to see more midfielders/attack minded players in there so that we're able to be more bold without compromising control and stability.