Waking away is a part of the negotiation strategy. It does not have to be always carried out. By mixing the two you are missing the point. Most of the time it would be an extra like dfk, bbbj or CIM. If the WL dies not provide something that you want normally you can’t negotiate. It could also be the WL wants extra for that service. For a successful negotiation both parties have to feel they won. Otherwise one wont be happy and you don’t want the WL or ML not happy as the service won’t be that good and you will regret not walking.