The scale is the thing that most bedevils me.
I was recently watching some commentary on house rules from [b]Lion in the Trenches[/b], who was reacting to suggestions that he place an Austrian cruiser in the Sea Zone off Tsingtao in his Global 1914 customization. He made the point that a single Austrian cruiser doesn’t scale with the squadron or fleet implied by the corresponding game piece.
By my estimate, Global 1940 models ground units at the level of army corps, naval units at the level of fleets or task forces, and air forces at the level of wings. There are a handful of exceptions for colonial detachments, such as the two starting British Infantry in Kwangtung (Hong Kong), which stand in for about 14,500 defenders historically. India’s potential as a source of colonial manpower is significantly curtailed by the British Empire’s income problems, and Australia often explodes in production by the end game (win or lose) even when their national manpower pool and industrial capacity would never have allowed it.
In my opinion, scale should be balanced rigorously against the opportunity for fun gameplay. In my Global War games, I always add a French Infantry in Indochina, for example. There is also a clear movement in favor of bulking up the Dutch presence in the East Indies when games of Global War are played, and many players prefer to give the Italian fleet-in-being a fighting chance with set-up variants to blunt the Taranto Raid.