Sorry, the information I was working from showed the Imperial Guard Grenadier and Chasseur battalions in 1805-07 with 8 companies (each of 80 men), and the later Fusilier Grenadiers and Fusilier Chassuers each of 4 companies (with 120 men, which allows for two pelotons of 60 men each). So, to be honest, news of a 6-company structure in the Guards derailed me.
In any event, my reading of the French "Rules and Regulations" (Sections 570-2) suggests to me that the regulation procedure is easily applied to any even numbered quantity of 6 or more divisions, so that it would not matter whether the battalion was composed of 3 companies in 6 pelotons, 4 companies in 8 pelotons, 5 companies in 10 pelotons, 6 companies, or 6 companies in 12 pelotons, and so on. But I am open to further education on that point!
Cheers - Howie