Fire giant druids gain absolutely nothing comparable of an advantage over a cloud giant. Both have very nice gear options and both have a decently easy vuln to deal with through gear/preps/skills but fire giants have a whole lot more enemies (not necessarily a bad thing). And ironically, I'd rather have had the flight and cloud giant edge for damage over getting ignite and having to cast windwalk (which I think was like 11% of my mana pool).