Oh man, that was one of my all time favorite fights. Wasn't 100% sure exactly how effective that tactic would be, but it goes down in my permanent playbook now.
Sometimes subbing stinks because you have to live with the choices the previous player made (not that they're necessarily bad, just not what you would have picked). Sometimes living with those choices and stepping into almost immediate fighting means you have to get creative. I'll try to write up an AAR tonight, good stuff.
PS I don't know why people pick misfortune so much. In the 4 (5?) turns I've taken so far I've lost 5 provinces to indie attacks, a temple, and bogus in sieging one of my castles. :/