“If there is no claim to exclusion from salvation, why do all of the different Christian sects war so vehemently with each other about who is right?”
If you think of the Body of Christ as a giant campsite with each denomination getting a tent... Most fights are caused by disagreements over how to contruct the tents and how to anchor them to the ground.
So Mormons profess Christ, then their way is just another way of putting up the tent?