also remember, it was common for French Corps/Div to be equipped with a full compliment of arms. The Corps de' armee system was setup so that a single Corps had the ability to fight on it's own a vastly superior force for at least a day or 2. That may also be what you ran up against. This was something quite different in European warfare, that is one of the reasons that Napoleon seemed almost invincible in the early years.
Good points, Leatherneck. I've been doing some testing on my own, and I'm unable to re-create the issue. I restarted about 5 sandbox games, division size, with Picton, and the French always roughly match Picton's numbers, with 3 infantry brigades and 2 artillery batteries. Occasionally there will be a brigade of cavalry as well, but the numbers on both sides are always around the same, and I haven't seen the 24 guns yet. We'll keep testing.
I have to ask the silly question, but are you sure you have the Balanced button checked in Sandbox?
NSD Map/Scenario Lead