I think this system allows for for one not to be needed, look at the change in Jack now he has more space without Gundo & Cancelo both looking to get into the Left half space on the move. Ake gives him an option but the space to drive more.
Gvardiol is a very accomplished left back i can see why he's probably the chosen one, progressive distance and carries hes on higher per 90 stats than TAA as it stands. Be interesting to see if/who they go for as a FB,
Livramento if/when saints go down might be a shout, like Hickey as well.