Forget salamander riders...we need Niefel Giant Mammoth Cavalry! Think of how much damage those could do...trampling sacred well armored good morale cavalry with axes for size 6 opponents. Just give them full plate armor and make them cost about 500 gold and 100 resources each.
Or maybe satyrs riding centaurs... or something riding cu sidhe.
But salamander riders actually sound like a pretty good idea unlike my mammoth cavalry.