Hehe. The Le Mans winning Audis are a natural extension/fit of the Audi road cars because Audi has been known to manufacture powerful Diesels for a long time. Also Diesel is available and socially accepted all over Europe. For Ferrari it would be trying like fitting that square pig through a round hole or something to make a meaningful connection between their Le Mans prototype and their road cars. Particularly in their #1 market, the US where Diesel is not really used for street cars, but trucks.
Brawn did it to Honda. Granted its two different series, but Ferrari could do it imo. Maybe they wont be champions the first year out, but they could do it.
Not sure I understand your point. What did Brawn to Honda? A Diesel powered Le Mans Ferrari would have zero ties to its road cars, unlike Audi or Peugeot.