Guilds are doing tank-prio on paladin tier, but mine isn't. How viable of a tank am I without tier?

Out of the 4 guilds that I interact with, 3 are doing tank-prio on tier to get their paladins the 4 set bonus. Afaik, that set's 4pc bonus is the best in the entire game (+10% consecrate). I also have mana issues on trash still, so the 2pc bonus (extra mana from healing) would be huge too.

I haven't been able to win any tier, and we still have 6-8 people on every single tier token. Hyjal and BT trash is still a slog, and I definitely think my lack of gear is contributing to that. I have phase 2 BiS, but it's still really lacking in stats.

I'm all for rolling out the gear, and haven't asked for tank prio. But the lack of improvement on my gear makes be doubt if this is sustainable. Trash should be getting easier, but it's getting harder as DPS get more gear and my threat is static. We are also trying to speed up clears, but the mana issues are getting worse without the set designed to help paladin tanks keep up.

This is all to say, I am concerned that without upgrades my tank gear is becoming a bigger and bigger liability. I also haven't done ZA or Sunwell, but I am concerned about gear in there too. If I have to wait 8+ lockouts to get tier I don't think I will be prepared. At what point do I consider a swap to holy or ret?