After more than two years of the front standing still I have actually managed to deplete the Griffonian griffonpower reserves and make their lines collapse.
I was expecting a much longer meatgrinder period, I swapped to the Empire with a command just to check what's going on for them and realized that their focus tree gimped them by locking their recruitment level.

imo the empire should have a special event that allows them to bypass that locked law in an event they start losing a defensive war, kinda doesn't make sense for them to just lay down and die because muh laws.