3-4-3 wouldn't change aything. Against strong teams you need to score from every possible chance and we missed all of them. We basically had 4 clear chances in 2 games (Messi 2x, Iniesta and Suarez). Problem is not in 3-4-3 or 4-3-3, problem is that we conceded 3 goals in the first leg and missed all we could in both games.
I am not saying that 343 is the answer.
But in this moment for our team, 343 is better than a horrible 433.
About our future, I am opened for anything: 442, 4222, 4231.
We will (imo) need something different.
This version of 433 is not working either in La liga nor in a CL anymore.
Remember that in 2016 we blew 10+ points advantage in spring and won a title luckily in the end.
433 managed to be 15 points behind Real in La liga over the last 12 Months, and in a CL we played extremely hot and cold, getting knocked out by AM and Juve with 0 goals scored in 300+ minutes in 11 vs 11.
Imagine having MSN and scoring 0 goals in 11 vs 11 in those 4 matches.
That's not easy.
1. we struggled even with Alves
2. we don't have a RB
3. LB Alba is like having a man down in attack
4. Busi is almost done
5. Iniesta is done
6. Rakitic is not our level
7. Messi is not on his prime anymore, plus he is drifting into middle all the time
8. Neymar can't score
9. opponents learned how to neutralize 433
Just way too many problems for a 433 to work.
So, for me personally, let's try 4-5 different formations during the summer.
433 didn't win 3 matches in a row in the last 12 Months, roughly. We slipped over and over once in 2 or 3 matches no matter against whom we played.