Barcelona has great players and they always work well together. For example, Lamine Yamal and Lewandowski work well together even though Yamal is a young player and Lewandowski is a senior player. This is the greatness of Barcelona, which always has great players and all players can work well together. Of course, Rashford can also play well and adapt quickly even though he has just joined the team.
It's absolutely true that since Hansi Flick joined, Barcelona has improved even more, and Barcelona certainly made the right choice in appointing Hansi Flick as their new coach. Currently, Barcelona is not yet in a safe zone, so Flick must work to make the players even better. However, Barcelona has managed to reach the top of the standings again, which is a good start. The El Clasico match will undoubtedly be more exciting, as Real Madrid will certainly aim to win and overtake Barcelona's position at the top of the standings. Unfortunately, there is still some time before that match.
Honestly, I don't think Real Madrid can beat Barcelona because, objectively, Barcelona is stronger now, and the match against Atletico showed that Real Madrid's defense still has many weaknesses. And before El Clasico, Real Madrid still has a match against Villarreal, who are currently the third team in La Liga with 16 points. I think that, despite this being a home game for Real Madrid, beating such an opponent will be a challenge. So, I think Barcelona's advantage can only increase in the coming rounds.
I don't agree with you that Barcelona is now stronger than Real Madrid simply because Real Madrid loss to Atletico Madrid. Apparently, this is Real Madrid first loss of the season after winning six matches consecutively. They may have loss to Atletico Madrid 5:2 in Vicente Calderón but it is not an enough reason to start concluding that Barcelona is stronger. Atletico Madrid isn't a small team in the La Liga,they are also capable of defeating Barcelona in a full time game. Furthermore,I think Real Madrid with definitely defeat Villarreal with a large margin. Villarreal haven't played any big team as strong as Real Madrid since the beginning of the season, they're only spotted at the top of table with 16 points because they have been meeting with smaller teams. If they can be able defeat Real Madrid at Santiago Bernabéu,then I will acknowledge them as a strong team. However, judging by the H2H between Real Madrid vs Villarreal,it's obvious that Real Madrid have won Villarreal far more times than what Villarreal have won them. Based on my analysis,I am confident that Real Madrid will defeat Villarreal.