I'm trying to set up the lists of preferred actions for my leader, but I'm confused about the meaning of the "Favored" and "Value" fields. I imagine that favored=true means that they want to build the item, and favored=false means they don't, and similarly positive Value and negative Value. But what is the purpose of having both? Should I set both? What is the significance of making Value=1 vs. Value=10?