I would suggest raising the cap to unfrendly to 11 points from 5 since it is rather low compared to kingdoms mostly beeing 22-25 provinces, but in return add that any province that gets attacked directly gets access to all hostile ops against the attacking kingdom or province for a duration of 12-24 hours after getting attacked to allow for t/m's to better defend against randoms outside war and to put a deterent against building military only provinces with weak tpa and wpa.