If I was to give all the intricate details of every spell and weaponskill right this instant, the post(s) would likely be too big to absorb. The original poster is starting out the game and first asked if he did more than just pop Tank Stance and spam an AoE like Total Eclipse. His latest question is a concern if the play styles between the tanks are any different. Maybe the big burst will be fun to see since it might look like buzz sawing the enemy during the time. This is also handy if an ally is caged by a mechanic and you want to help burst them out now. If he does want some more details later for the combo bonuses and what exactly each tank mitigation cooldown is, we can help with that. It may be best to let him pick one class first to ask for these details. It is still appreciated that you are adding more to this, Claire.

As for the Gunbreaker part, I simply meant you can't just use Rampart and Heart of Stone in between one off global gap and hope the Continuation buff stays for the next one. You lose that particular Continuation buff doing that unless you purposely stall the GCD usage. It's not impossible to still get both tank buffs up during this time without clipping the GCD much. They just have to be used one at a time for each off global gap. I underlined the GCD skill used.

Gnashing Fang > Rampart + Continuation (Jugular Rip) > Savage Claw > Heart of Stone + Continuation (Abdomen Tear) > Wicked Talon > Blasting Zone + Continuation (Eye Gouge)

This is just in theory assuming you can attack the boss. If the first off global gap had Rampart + Heart of Stone instead, Continuation (Jugular Rip) would fizzle and change to Continuation (Abdomen Tear).