The short answer is that there is no precise official answer that applies to all countries in all situations. A&A Global 1940 is a strategic-level game, and as such its units are very roughly supposed to represent large formations like army groups and naval fleets…but they can’t be pinned down more preecisely than that, and even within a single broad category (like air units) you’ll get a lot of variations for lots of reasons. Moreover, the allocations of units in the set-up charts seem to reflect more that just numbers, and seem to vary from country to country. Here’s one example. According to the set-up charts for Europe 1940, Germany has a total of 3 tanks in Western Germany and Holland / Belgium at the start of the game. In real life, in May and June 1940, Germany had about 2,440 tanks in those areas. Technically, this would work out to one tank unit representing 813 tanks. According to the set-up charts, France has only 1 tank on all of its territory, so in principle this ought to translate into 813 real tanks. In real life, however, France had about 3,250 tanks in May 1940, or about 50% more than Germany. I assume that France is given so few tanks in the set-up charts to reflect, in part, the fact that the game starts in early June, and thus that France has already lost some of its tanks in May, but also presumably to reflect factors that have nothing to do with raw numbers: for example, the dispersion of the French tanks along the front, their lack of radios, and the French doctrines that viewed tanks a local infantry-support weapons. So a single A&A unit can’t be rigidly translated into a precise number of military forces that would apply accurately and uniformly to every country in the game.
In the game you’re designing, your best option would be for you to figure out what the units need to represent in your particular game, rather than trying to figure out what figuring they represent in A&A and then translating those figures into your own game’s context.
