What if at the Battle of Marengo, General Desaix is not mortally wounded following his crucial, battle-winning reinforcement? Other than this, nothing is changed about the battle.
Given Napoleon's friendship with him, and his talent as a commander- his exploits in Upper Egypt were far more impressive than the majority of Napoleon's battles in that campaign- how might he rise, and how might he effect the wars later on?
Now, on the same day in Cairo, General Kléber was knifed through the heart. Let's say this is averted as well. While his relationship with Napoleon was rockier, he too was a talented general, and administrator.
If these two notable men live, how might the course of the Napoleonic Wars have changed?