I'll agree that STR is out of place but MND makes sense. Mind affects healing magic potency which is a part of what Paladin does, heals itself and others. Also let's not forget that Mind also affects the Flat blade combo which is one of Paladin's enmity generators. I think VIT/MND makes more sense. DEX may affect block rate but I don't know by how much and if it's even worth it to stack. I would stack block rate gear or use a higher block rate shield.