A repost that I had in my "Paul's Ponderous, Pompous, Pedantic Proclamations, Patter and Platitudes" thread (that was not reloaded) outlined my views on squad composition. In that I put forward the idea that the number of manual bolt action rifles was nearly irrelevant.
For the most usual 4-X-Y squad which represents most nations' squad with a single LMG and the rest rifleman (possibly a single SMG), 1 FP represents the LMG, the other 3 FP represents that there are some riflemen. Those 3 FP are more a psychological thing than a real physical threat, the fact that someone, anyone is firing regardless of effectiveness. Reduce by 1 for particularly bad or unmotivated troops (Ax Minor, Italian, Partisan, etc), add 1 for each LMG and just possibly add 1 for particularly high quality troops (mainly to give a CC boost). Ditto add 1 if the majority armed with semi-automatic rifles (US Garand) or 1 for roughly each 3-4 men armed with SMG.
The reason for my conclusions were that the bulk of bullets (FP) came from LMG and SMG with a small edge if equipped with semi-auto. The bolt action rifle really added little to squad FP, so a 7 man rifle squad with a LMG would be little different to a 12 man rifle squad with a LMG in terms of killing power. Add a 2nd LMG or replace bolt rifles with SMG/assault rifles and that is a different story. I also decided from my analysis that ASL does not really distinguish between LMGs, a BAR is the same as a MG-42 when an inherent LMG, though the MG-34/42 does always give spraying fire. While that may stick in peoples' throats, there is some logic to it as that squad has to haul the LMG ammo to last them anything from a few hours to a few days and will rarely simply blaze away using the full capacity of their LMG (OK, face a Banzai charge and all bets are off).
As an example, consider a 10 man German squad with 1 LMG, 1 SMG and 8 rifle men. Assume the LMG gunner and squad leader carry 1 250 round can and each rifle man carries 2 for a total of 18 cans or 4500 rounds, about as much as is practical. A MG-34 will fire all that in 5 minutes, so to last for, say, 4 hours to a day, the MG-34 will have to be used sparingly. A BAR is not really much worse in such circumstances. A MMG/HMG or to some extent an extra (SW counter) LMG is a different matter as they, presumably, represent not just the extra MG but a mass of extra ammo and somewhat better gunner(s).
So in the end the number of bolt action riflemen, according to the existing ASL pattern, makes little difference, just the number of SMG and LMG.
As for estimating the number of squads? Ideally you rely upon the size of the formation, an early war squad often contained 4 squads, some 3, by mid war a platoon had just 3. A company had 3 line platoons, some with a small MG or lt. mortar platoon, a battalion had 3 line companies (4 for British) with 1 or 2 support companies. The higher the level of a formation (or the bigger the total number of troops) the higher the number of auxiliary troops, whether specialist weapon crews or supply, command, comms, etc troops. So if you are dealing with an around 10 man squad, for <100 total divide by from 11 to 15, <300 divide by 15 to 20, etc.