In America's land forces,I understand that the army has a larger "tail" than Marine Corps, either tail being more than 90 percent of the total in uniform. Having pretty much no information of other western and European land forces, I anticipate America's land forces will have more tail than any other country's — mostly because huge budgets almost certainly translate to enormous bureaucracies and waste.

The first war that included significant use of metallic cartridge repeating firearms was the American Civil War 1861–65. What were percentages of soldiers within combat arms of Federal and Confederate land forces?

During the Great War what were these percentages among British, French, German, and Russian land forces?

What would be the effect on land forces' combat arms percentages of countries with smaller populations and smaller industrial bases, such as Imperial Japan during World War II, Italy during the Great War, Israel today?