Seeking explanation: Why cant we make 3 midfielders work?

We have I think the 3 best midfielders in the world. How is this not enough that we need to have a 4th one at the expense of creative attacker?

Seriously, how imbalanced is this squad where we have many attackers but can only play 1 at a time + Lewy.

And have 6 midfielders but play 4 at a time?

<em>This does not represent the views of Barca Blaugranes or SBNation</em>