If Mister was in charge of Barca, we would've been in the relegation zone. With all the injuries.
Have you seen the number of key players don Ernesto is missing almost every game? Prados and Egiluz (who had a great loan spell at Mirandes last season and was projected as a starting CB or at very least important rotational player) out for season with ACL while Yeray is suspended until April. Nico is far from his best playing through the same injury than Yamal, Sancet never been fully healthy, Inaki been out the last two or so months as well. And yet they are still competing for European spots while playing in the CL which they are not used to do.
Not having a reliable striker is their biggest weakness but not much they can do about that. Llorentes and Adurizes don't grow on trees. They are massively underperfoming their xG, only Rayo has slightly worse npG vs npxG and only Oviedo a worse conversion %.
And on the other side they are missing two key CBs as already mentioned while Laporte has also not been good after playing semi-retired alongside Siunaldo in a top 5 league for a few years. Unai Simon had a few clangers too like against us when he gifted us two goals.
So mister would do perfectly fine with this Barca team with all the attacking talent we have. And we wouldn't look like a 4th tier team defensively.