I would disagree with trying to expand, sit tight and the revolting provinces end up revolting back to you anyway. What is causing me strife now is the hords comign into my lands. Luckily they seem to go for settlements with large stone walls so only rams and seige towers to worry about. They only ever seem to build one of each to missleing the ram then putting all you troops round the entrance to the seige tower makes a nice slaughter house. Eventually they wont have any foot troops so cant re-siege.