Setién has so far made an excellent impression and I am very excited about the first appearance. I believe we will see some changes right away. Reason: many of our players don't have to learn a new game, because they already know this way of playing. It is not the case that Setién implements a revolutionary game, but simply goes back to the roots. It will certainly not all work out, but I expect that you will see the handwriting of Setién. Especially in the building game.
The squad is not perfect for this type of game (lack of speed of central defenders, no real wingers), but there is still a lot of quality in this team and there are tactical options to deal with these weaknesses. Making them run more/more effectively in terms of team movement as a unit + more motivation can do a lot right away. They were lacking intensity.