The travel distance is too far while having only 6 armies making it impossible to fight invaders.
OK, I took over 6 region thats around 10ish cities and still limited to 6 armies only.... Is this a bug?
There's a nice mod over on twcenter that increases the amount of available armies/agents you get with each increase in imperium.
If you don't like being limited to 6, that should help you out
Is it the Grand Campaign minimod?