Hauptgrate's comments were so good I took the liberty of pasting them back to this, the correct thread. I hope you don't mind Hauptgrate!
To echo your comments, the same applies to modern war too. In Viet Nam at the platoon level the M60 was generally assigned directly to individual squads instead of being kept in a weapons squad. And total platoon strength was usually no more than two squads and often only one! At the company and battalion level units were often left behind to provide higher level CPs with security.
The book "Red Thunder, Tropic Lightning" provides an excellent overview of the theoretical organization and reailty. After providing security elements for higher level CPs and rear areas and accounting for MIAs, WIAs, KIAs, and those on R&R units could routinely operate at half strength. One veteran in the book notes that his rifle company had an authorized paper strength of 188 but usually went out with 80-90!
Another book about Operation Anaconda in Afghanistan also explains how lift capacity in helicopter operations can also severly limit the assets available to a battalion or company commander (in this case the couldn't take their mortars along which proved to very disappointing!).
Finally, Hauptgrate's comments about the 57 also demonstrate just how much varience there can be between units. I too have read that many 57mm armed units were converted to rifle platoons (same happened in Viet Nam where many battalion/company-level mortar units served as riflemen since the 81mm and 60mm weapons were tough to hump in the jungle and many units operated with plenty of arty support).
But while at the Tank Museum in Virginia I met a vet who said that his 57mm ATG unit fought from Normandy to Germany with the 57. Their usual procedure was to shoot the tracks of heavier German tanks and to then call for air support to destroy the tank. They also shot the horses of German ambulances since these horse-drawn vehicles often carried ammo rather than casualties.
Basically they functioned like a 57mm sniper team! And while many vets were convinced that every tank was a Tiger and every gun an 88 this veteran said that his 57mm platoon proved useful precisely because such heavy tanks were rare and the 57 was accurate enough and powerful enough to handle the more common light and unarmored German assets.
On the other hand (starting to sound like an economist) I've also read that lighter guns often served forward of heavier ATGs to provide a defense in depth. For example, the Russians would place lighter ATGs in hidden positions along the anticipated route of an enemy advance. But instead of being positioned to engage from the front they would be positioned to engage from the sides and rear. This way they couldn't be engaged at longer range from their own front and they could ambush targets from the side where armor was weaker.
So I suppose it all depends on local unit practices, the needs of offense and defense (ATGs do make terrible assault assets!), and the availability of resources (if a more useful resource is available that gets used while a useless resource get's converted to something else).
Hauptgrate wrote
I have run in to the problem with 5-1 for many years as I play a Command Decision based game. When organizing my armies, I worry more about the balance of weapons rather than the strict 5-1 ratio. sometimes this means bumping up weapons one level -- two MGs per company would bump up to one MG stand per battalion, etc. The whole thing about TO&E somtimes makes me laugh -- units on the actual front lines were rarely at full strengh and/or often had substitute or unathorized equipment. The above example with the 57mm ATG in American armored infantry bats is a good case in point. A collegue of my father, and one of my high school teachers many years ago, commanded an M-5 Stuart in the 4th Armored. When I first started wargaming, I recall him shaking his head when he saw us using the 57 to support an assault by armored infantry. He said most common use of his tanks was in infantry support and that he NEVER saw a 57 anywhere near the front lines. In fact, he rarely saw a 57 at all, except in the depot -- where there appeared to be plenty of them -- or sitting abandoned along the roadside. Basically, the troops found little use for the heavy gun and got rid of it as soon as possible. My gaming armored inf bats have just one stand at the battalion level representing the few that might have been kept around. Another case is British reconnasance units, which have quite a large number of scout cars and such. Gamers need to understand that besides actual recon, Brit recon units were also tasked with traffic control and communication line security. Soooo... remove about half of the scout cars and bren carriers from the board....they were busy doing other duties! My point is that TO&Es should be taken as a guide, and in a 5-1 scaled game, imperfect adherance to the exact ratio can be explained in many ways...