The gods hate mages. Upstarts who wield magic without reverence for the gods. So they refuse to allow their clerics to heal mages.
The dwarven gods true names can only be known by dwarves. They are referred to by nicknames in the presence of non-dwarves. I.E. Gudurran( Allfather) Baenna ( Hearthmother) Dudrak ( Ore), etc. No torture or magic or direct intent can reveal their true names to non-dwrves.