Barcelona don't need to be good to beat Real Madrid, if you remember last season when Barcelona weren't at their best and even Xavi started to mix the team in the middle of the season. This means that Xavi did not build a team from scratch and only took advantage of the squad that existed at the time, but what happened Xavi could actually provide a good strategy for Barcelona to beat Real Madrid 4-0. So if it's just to beat Madrid I'm sure whatever squad Barcelona have at least they have a chance to win, but if it's to be LaLiga title winners then of course they need a better team and this season they've had it.
and how can you beat a tank like Real Madrid if you're no better than Real Madrid?
sorry your thought escapes me, in my simple thought, to beat the opponent you have to be stronger (or luckier).
I don't understand, can you explain better what you meant? Because something doesn't come back to me.