I think that's where I was heading.
I suspect the early successes of massed French Heavy cavalry was due to facing poorly trained conscripts or at least reluctant aggressors.
However, Napoleon's armies exploited these successes by better organization, training and propaganda...and I'm sure for their parts, Murat and Ney might have been astute judges as to when to deploy massed cavalry.
Certainly the use of the Prussian cavalry at Auerstadt was poor judgement, while employment by French at Eylau was better judgement...or would you call it desperate? What's a good example of astute judgement in the employment of massed cavalry?