I'm not saying RDruids are or aren't too strong, but comparing abilities in a vacuum like this never turns out well, especially when you present all tools as if they're equal. For instance, both cyclone and root have a cast time that you didn't present, does that make it a fair balancing mechanism? I'm not going to say, but just things to think about.
I really think thats just a case of mages being too tanky, which is why I suggested a flameglow nerf. I really don't think mage/rsham, mage/priest, mage/hpala are that great outside of rogues and sps. Decent comps sure, but not anything super dominant, especially when you take away flameglow
mages are completely fine lol, have they even seen combat rmd/godcomp? (godcomp can lose to some stuff, rmd should never lose ever)
I would say you can hit overall game balance issues more effectively by toning down druids - who are dominant in literally every aspect of the game, and every comp in PVP is just straight up better with a druid healer, something that hasn't ever really been the case before -, and combat rogues.
I'd say with a hit to mage survivability (like a flameglow nerf, and tweaks to alter time/ice barrier), and toning down druids, which I think is necessary for game balance all around, that mage comps wouldn't be anything too special. Those comps literally just thrive off of class synergy and not because mages are super strong as a class.