There's a lot of good points in the video.
It was said that only Gundogan and KDB are the players to provide fast and precise through balls to the attackers. However, oposition have recently man marked these heavily. And this has paid off in the recent games. My thought why these two didn't start, was that maybe Pep wanted to confuse the opposition by using them later, off the bench. And before that, play it solidly and with low risk (low focus on pace forward), with an unformiliar formation. Riding the storm and holding back the move to introduce the best attack serving midfielders could have paid off, however, the early goal against fecked up this plan.
If it had succeeded it would have been called a master stroke. Just a thought.