Probably the most able field commander of the age, bar Napoleon.

Davout was extremly competant and won several battles independantly of Napoleon's presence.

At Austerlitz it was his Corps rapid marching that enabled them to close in on the Allied forces, a feat that could only have been achieved by the men being inspired by the knowledge of their commander's care of them.

At Auderstadt he beat the bulk of the Prussian army with just his Corps, whilst Napoleon dealt with the smaller of the Prussian forces.

In the 100 days campaign leading upto Waterloo, Napoleon made a huge flaw in putting Davout in a wasteful ministerial role, and Soult in the ill-advised role of Chief of Staff.

Davout or Soult leading the forces entrusted to Grouchy or Ney during the campaign would have been far more suitable, and who knows, the course of history may have been different as a result.