Gallia has a population of 430.000 persons give or take a few thousands. In peace time they have a standing army of ~92.000 which is equivalent to 21.395% of the population. Seems like they missed a zero or Gallia is a heavily militarized kingdom bent on world domination.
Not really. Say they have mandatory service for 2 years with a 10 year reserve. 21% of the population doesn't seem that far-fetched.
http://www.statcan.gc.ca/tables-tableaux/sum-som/l01/cst01/demo10a-eng.htm
Canada's population of 20-34 year olds is 21%.
Plus this game men and women serve, so that's only 10% of the male population, which isn't a lot.