Just looking at Argentina as a team. Barcelona could replicate something like that on CL level quite easily. We just need few modifications.
We need players who run their socks off, all the time, relentless midfield, defense, and striker. This means Messi can chill and wait for good spots to attack.
Basically: We need to throw away Busi. He would get murdered in yesterday's game. Brazil would run past him 50x times. WAY TOO SLOW. Simple as that. Defense is priority #1. We need to fix that.
Every player needs to contribute to defense, par Messi of course!
That's why it will be nearly impossible to play Aguero and Messi together. They won't work together. The work rate is fecking minimal if they both play.
I would only play Aguero and Messi together if we know the opponent parks the bus. I don't think Aguero will be good for us with Messi, especially versus good teams. They leave too much work for others.
Sign someone NASTY to midfield/defense. We need some balls. The alpha mentality is missing from Barcelona. Starts with a lack of leadership from the goalie, of course, Stegen. Alba is a good player, but mentally weak and shit defensively, BUT we don't have the money to find a replacement for Alba, so keep.
Midfield needs that insane physical machine. Pedri and DeJong would need to take more Busis role and provide offense, but again I doubt offense would be our problem vs top teams, it would be defense. As long as you have Messi, Fati, Griezmann.. You will score enough.
Pique and Lenglet are a joke and should never start a match together unless it's a charity game for fun because they will guarantee a lot of goals on their own end.
MY POINT: We can't build a dream team of Guardiolas, but if we build a super hard-working team with few offensive superstars, we can still be a top team and CHALLENGE ANY TEAM IN THE WORLD..
Sign: Leader to defense. Romero (type of guy) and DePaul to mid and a striker who work their socks off.
and sell Stegen for someone who can catch the ball under pressure.
Yes, it won't be "Barca DNA football", but we can win something.