Fighters are good, but early game I've found the best option is to go hunters with the bird in the hand upgrade, around mid game about three or four fighters will kill a dragon pretty quickly, and if there's water around the ships with aa (forgot the name) three of those will be pretty much impossible for a dragon do counter. Grenadines currently suck at anti air but are great vs ground armored units and anti-air turrets are worthless by themselves vs a dragon. That being said if you don't use dragon mode your probably going to lose, if you suck at dragon vs dragon combat, just don't target dragons go for buildings, small number of units, and cast buffs for your units especially healing/armor spells. Oh and when your getting hit spam that right click like your life depends on it, because losing your dragon is a big hit to your eco especially early game