In WoW terms at least there's plenty of wyvern-style dragons that have visual differences and are distinct, so I wasn't sure! I also wasn't sure if all the Serthica dragons were always 100% fire breathing since a lot were.... gone.... once we turned up... But Wrathion wouldn't know that either since he never asked! A different skull shape would be enough to be like 'well this isn't likely IMMEDIATELY related... probably'.