Madrid tactician Mourinho assembled an offensive forward line of Benzema, Gonzalo Higuain and Cristiano Ronaldo during his side's eventual 2-1 home reverse to arch rivals Barcelona in their Copa del Rey first leg quarter-final encounter.
However, French international Benzema echoed his belief that the attacking triumvirate did not pay off against Pep Guardiola's charges.
"It's a 4-3-3. Pepe playing in the middle is good, but it is true that the frontmen find it difficult," Benzema said, according to AS.
"However, it is something you have to sacrifice."
"We fought well in the first half, but it is a bad defeat - we lost at home, but still showed an intent to win the game," continued the France striker.
"Barcelona are a good team, but so are we."
Nine-time European champions Madrid return to domestic action against Athletic Bilbao on Sunday.