I'm playing Peninsular with them. Army lists are pretty easy to work out except that I think the term Brigade is something of a misnomer.
From the lists and games I've seen they are not 'Brigades' as such. They look to me to be more akin to bath tubbed divisions.
I was already playing my games like that anyway, so it was great to find this set of rules was doing, or felt like it was doing, a similar thing.
I've generally played (and built my armies around) one unit is a thousand men. A division is the basic building block of an army (I don't do brigades as such).
Example: A typical British Division has 5000 (rounded down) men for five units. Two thousand are Portuguese and 3000 are Brits, so two Portuguse units and three British units. Any Cacadores are fielded as skirmish line bolsterers (SoN detachments). That works very well with SoN.
Example: 1st Division is 7000 men (rounded down) and has (in my warped world) 2 guards, 2 Scots, 1 Scots light infantry and 2 KGL. Although the rules say six units max to a brigade, it does have seven unit brigades in the lists for 1813.
7000 men (rounded down) is about the most you find fielded in any British or French divisions, with most having 4000 - 6000 (rounded down), so that fits in very well with what you typically field as a 'brigade' in a SoN game.
I play the key commander as a 'Corps' / 'Column' commander rather than Divisional commander and when a 'Corps Commander Arrives' Event card is played, I simply mark the command stand and call it "Corps command clarity." When the Corps commander is killed (Event) or goes off elsewhere (End Phase) your force commander loses "clarity". This has worked seamlessly.