One last point: you severely mischaracterized our Roma/Liverpool defeats if you think they are down to our inability to handle high balls.
It doesn't have to be only one.
You can have a perfect midfield and mentally strong team, but a short team will still concede a lot against European opponents.
And please don't reply: but Pep's team...
What if:
1. there were no Italians back then due to calciopoli and bankruptcy of Milan and Juve?
2. best English teams were Man Utd and a little Barca Arsenal, who don't play a physical football
3. Bayern had the worst era ever
4. there was no Atletico
5. there was no Psg
Teams were less physical back then, Epl wasn't rich, there were no oil clubs, Milan, Juve, Bayern, Atletico, Liverpool were clowns back then.
So, in that era it was possible to survive with guys who can't defend on corners.
Sadly, time is not standing still and we are in 2020 today.
Teams are richer, more physical and athletic.
And their default game against Barca is:
1. play physical, lots of duels, fouls and dirty tricks
2. run more than Barca
3. try to kill Barca on counters since we have slow players
4. try to hurl as many long balls, crosses and corners in the box. 2-3 of them will end in a net in this or that way.
If you have any hopes about a CL, you need to find an answer:
1. how to break buses in attack
2. how to win physical duels in midfield
3. how to run more as a team
4. in defense: how to prevent counters (due to our weak pace) and 20 crosses into a box (due to our poor height and aerial game).
5. improve mental strength of our (physically weak) choir boys