Real Madrid has adapted to the depth of its squad this season. They don't seem to have many problems winning matches, but that doesn't mean they are perfect without any flaws. Real Madrid's defense has been hampered by injuries, while they also lack quality strikers when they need them in big matches. If someone is worried about Real Madrid against Atletico Madrid, then I would also think that they would also be worried about Real Madrid against Barcelona.
Realmadrid is one of the best performing team in the world currently, they're doing great in both the UCL and their domestic league, Realmadrid are also currently the leaders in the Laliga and in their group in the Champions league and are also very strong contenders in both, and i believe they'll go far in the both league.
In as much as Madrid's defense is being hampered by injury, they've being doing fine and winning their matches and the only match they've underperformed so far is the game against Atletico Madrid which was due to errors from their defense line, apart from that they've been very brilliant this season, well Atletico is more good defensively than Barcelona therefore i think Madrid would not find it difficult scoring against Barcelona in the El Classico this season.