If you really believe that is how the game will go then I guess you haven't been watching this Barcelona. Barcelona have conceded just 4 goals from counter attack this season and have conceded 7 goals in the league. The last goal they conceded came against Betis and it was an own goal. The defense is the best and most inform part of Barcelona this season. Injuries made them concede that much against Bayern.
The game against United is going to be very tactical and if United want to depend on counter then they'll lose.
You can't convince someone who hates Barcelona to say Barcelona are better this season, it's useless. Lol
I support what you say because I hardly missed a Barcelona match this season. I admit that they have developed well in La Liga by bagging 53 points in 20 matches and conceding only 7 goals. But that can't convince someone who doesn't like Barcelona even though Real Madrid have been playing so badly lately.
The Europa League might be different because Barcelona will be up against Premier League team, and this is match that should be difficult for both of them. After all, Manchester United are also not really weak and they are also not really strong on all fronts, so there must be gap for Barcelona to score goals in the two meetings later.