Davout was regarded as ruthless in his own time, his reputation in that respect is like Bernadotte's for unreliability: often when you look closer at an individual incident all is not as it seems.
Davout's conduct at Hamburg was considered close to a war crime, possibly if he had been tried he would have been acquitted: possibly if Dupont had been tried instead of being put before a rigged court of enquiry he would have been acquitted too. Dupont's reputation as a man and a soldier was pretty good apart from Bailen.
If Bernadotte's bad reputation is to be used against him in discussing Auerstadt then Davout's is relevant to Hamburg and Dupont's good reputation should be considered in regard to Bailen.
regards,
Susan