Thanks. A part of my brain recognised those facts once you had committed them to screen, but was being a bit old and slow recalling them unaided.
So presumably one of the fusilier companies paired off with the grenadiers in two-company wide columns?
It is actually a tad more complex than that. The basic tactical component of each battalion was the
peloton rather than the company, which was primarily an administrative entity. Per the 1791 drill manual, a nine-company battalion was supposed to form eight
pelotons in order to manoeuvre in column and then deploy into line : since some companies were inevitably stronger than others, the
pelotons had to be formed before going into action to ensure each had enough men to occupy its ascribed frontage, which means men sometimes had to be transferred from one
peloton to another to make sure all were the same size. Generally speaking, 100 men was considered the desirable size for a
peloton, which meant an eight-peloton battalion was supposed to be 800 men strong - very close to the paper strength of a French infantry battalion though such numbers were rarely available after a few weeks' campaigning.
In a perfect world, the grenadiers and the seven fusilier companies should have neatly divided into eight
pelotons with the voltigeurs detached as a skirmish screen. In practice, battalion commanders and their adjutants were often forced to do a fair bit of tinkering and to redistribute men across the various
pelotons to ensure the battalion could function properly, especially in column. Keep also in mind that the grenadier company in a pre-1808 battalion only had a little over 80 officers and men against around 120 for the fusilier and voltigeurs companies.
This explains why the 1808 regulations which established the new six-company structure made life infinitely easier for infantry battalion commanders : all six companies had the same paper strength of 140 men but usually had about 100 under arms in the field, meaning each company was effectively the equivalent of a
peloton. The Osprey Elite book on Napoleonic French infantry tactics by Paddy griffiths has a few schematics showing how a pre-1808 battalion worked in the field, and particularly how its eight
pelotons were supposed to deploy into line after closing in on the enemy in column formation.