sending a searcher may yield special items to increase a lord/vassals stats a crap load (by 30 or 40)

put a person with good charm in a territory and give a hundred food 3 or four times and get max loyalty the4n put a person with high politics and cultivate till it gets to 100 and every september you will have a cash and food cow

i some campaigns some people will always defect just save and load and check every one every so often. hint Pender in campaign four will always leave the king eselred about 2- 12 month into it.