Tell your healers to man up. You're fine in terms of squish factor for tanking all raid content in the game. Unless you're turning your back on the boss or not using your Cooldowns properly, they have nothing to complain about.
You don't mention Rend or Thunderclap. I hope you're doing both as well as Cleaving multiple targets. Calling Heroic Strike a rage dump is a bit of a misnomer, you should almost always have the requisite rage to Heroic Strike and you should be using Inner Rage as well to make it pump faster. None of that has anything to do with your squish factor though.
For major glyphs personally I prefer Thunderclap/Cleaving/Shockwave but to each his own.