That line up looks frightening at first glance but who will help the defense? That is perfect line up for breaking scared opponents but someone like Atletico Madrid, a team which can defend and be dangerous on counter attacks would tear them apart. There is way to much finesse in that team and way too little real fighters.
That's the beauty of 4-2-3-1 IMO, despite imposing more defensive responsibilities on the team generally, 2 players in defensive midfield position would likely cover up the tracks, Busquet and De Jong would do, the only vulnerability I see is that the 3 Attacking Midfielders would have more work load as well and the striker could get isolated upfront more often than not.
That is a good formation but I don't see it working with this Barcelona line up. At least 2 from 3 attacking midfielders have to help in defensive phase and I believe only Griezman would do that. In modern football I don't think any team or formation can cover up for more than 2 players. Add to that the fact that Alba will also be in the opponents half all the time and you have a problem. Barca needs that left attacking mid/winger, position which would probably fall to Neymar to cover for Alba and that will simply not happen.