And let's not forget the other theatres outside Belgium:-
* Internal uprisings against Napoleon in Provence, Brittany and La Vendee
* Murat v Bellegarde in Naples
* Rapp v Wurttemburg (very last battle of the Napoleonic Wars at La Soufel - a French win!)
* Wrede's Bavarian/Russian corps attacks Nancy
* Lecourbe (mainly National Guards) v Colloredo in the Jura
* Suchet v Frimont (Austro-Sardinian) in Savoy
* Brune v Bianchi (Austrian) and Hudson-Lowe (Anglo-Sicilian) around Marseilles and Toulon
And if all that doesn't work, you've got 150,000+ Russians under de Tolly (who arrived just too late for the real thing).