Your choice of gear should really depend on whether you are the focus target and if you aren't whether you are able to win a potential 1:1 against the remaining opposing player. I recently formed a team on my old main (my rogue) and I'm playing with a priest. My gear is pretty outdated by actual standards and if I get focussed (which does happen sometimes, especially if my priest gets CCed after a few shots have been traded) I need survivability, at least a little bit. Burning your cooldowns will help certainly but on their own they won't carry the day imho. And as Tikii said, swap you gear if needed. On my warrior I now routinely grab my resist gear for my 2:2 team (I'm just waiting for the next double ice mage team that I can cheese with my Hydross gear
).