"French Company Size" Topic

I am reading John Lynn's book on the French army of the 17th century wherein he talks about infantry company size varying from 100 to 50 to 35 to 45 and back to 50.

Why the changes? Do smaller companies lend themselves to easier movement in the field? Or did they run out of qualified captains? But why tinker with plus or minus 5 soldiers?

Any thoughts?

Not sure about the 17th century, but in the 18th century companies were administrative and not tactical units. On the day of battle, troops would be divided into 4 divisions and each division into two peletons.

during the Seven Years War de Broglie divided the infantry in his army into 4 divisions. I believe he used the term from the 4 units a battalion was divided into for battle.

The most likely reason for such variation is the difference between peace and war. Fewer units were maintained in peacetime and they were usually at significantly lower strengths.