When my brother was younger he worked for a guy who used to say, "The road to hell is paved with good intentions." I'd like to think that Hanun's advisors (the princes) had good intentions in the advice they gave to their leader, but their advice was dead wrong. Unfortunately it's not enough for a person to have good intentions with what he or she say or does. In this situation the people to whom David was trying to be friendly became a "stench" to him and the focus of military action because of misguided "good intentions." It's not enough to have good intentions. Actions should come from something other than good intentions.
What impresses me about the Israelites during this period of their history is the way they looked to the Lord for direction in everything. With David it didn't come down to good intentions; it came down to seeking the Lord for guidance and following the guidance he was given.
Do you find yourself with lots of good intentions that end up creating problems? If so, then you might consider seeking the Lord. Thankfully the Author of this great story knows how to direct those who are willing to listen.