I think anyone can do good with Madrid, obviously a decent forward though not some crappy relegation team striker. Adebayor, Klose, LLorentre, Lukaku, all good and effective, but someone with Klose's profile might be the best bet. Also this is in no way crippling of Benzema's confidence. They have to get a second striker even if they had the best CF. You can't compete on all fronts with only Benzema in front and probably Ronaldo moving to fill the role at some point.
It's simply time for Benzema to step up.