Sentence:  In selecting Bran Stark, the lords of Westeros are choosing to value these stories and memories above whatever other qualities might make a good ruler, and more specifically, put an end to the caprices of heritage that have allowed bloodlines to wreak havoc on good <WSD>stewardship</WSD> of these kingdoms. 
Meaning of the word marked with <WSD> tags:  The act of caring for or improving with time.