Germany is no Finland though, Finland also largely have had mandatory conscription due to not being a member of NATO;

Germany would have an easier time maintaining an army alike the way France does, a fully professional large army and riot police basically being intended for maintaining occupied areas (Gendarmerie). Germany can in theory have a 1 million strong force, fully volunteer based. While Finland can have 3 million in the reserves, by forcing everyone and their nan a mandatory conscription service.

Conscription is the cost effective option if you think numbers is everything, but for larger countries you’ll get stronger militaries by keeping soldiers stay in professional lifetime careers