I never blamed X-I for losing to bayern.
And ofc the defense was shit back then.But,you don't lose 7-0 just because your defense was shit and the attack doesn't press enough.Anyway,what i am trying to say is that the X-I-B trio started showing signs of decline 2 years ago.We can't expect them to regain form now.
As you stated,the biggest problem the past 2-3 years is the tactics and management.It is obvious that,even if you have the best players available,if your tactics are shit and you cannot motivate the players,then it results in this situation.And Tito,Tata and especially Lucho (and the 2014 Tata) failed miserably.The problem started back in the last Pep season.We couldn't break the buses easily anymore.And instead trying to solve the problem,we stuck with the same players.Now,we have reached the absolute bottom.It pains me to watch the players doing nothing on the pitch and dropping points to Granada,Celta,Getafe,Malaga etc.To sum up the problem is:
Other teams defend better season by season+Unmotivated (old)players+really bad static tactics=failure to score a single goal
Nowadays,we really struggle to score the first goal.But,if we do,then it is fairly easy to score more goals,as the opposition doesn't park the bus anymore
What should be done is try to find a coach that can motivate the players and implement some basic attacking strategy,with decent movement off the ball etc.I am not confident Lucho can do that.Finally,if i was the coach i would rotate(50/50) Mascherano with Busquets in CDM,so that Busi can wake up a little bit.Then,i would give Rakitic the CM spot.Xavi should come in as a sub.Also,i would try Samper in the CM spot.Finally,i would also rotate(60/40)Iniesta and Rafinha in the CM/CAM spot,waiting also for Denis Suarez to return from the loan