Captain tanking needs a nerf!
I really hate calling for nerfs on any class actually, since in the past nerfs were often either pointless (e.g. that one time early on this year when a few lightning rk skills and a few burg skills got a damage nerf - before the fate bug got fixed... anyone remember that? lol) or way overtuned completely breaking a skill or even an entire trait line (RIP hammer down, execute and rk dps).
When lightning rks were dps meta earlier this year they were just overtuned in dps and had more utility than hunter and champ, that combined with a trivial rotation made them just stupidly strong for basically no effort at all.
But Captain tanking is broken in a completely different way. They have a massive morale pool paired with a huge amount of passive or easily maintainable active incoming healing (without need to invest into it at all), they have very reliable and easy to maintain self buffs (battle hardened, sure strike, pet) that add up to a large amount of damage reduction and they have a large amount of reliable cool downs that either have a high uptime (fighting withdrawal and to arms mainly) or longer ones that pretty much guarantee you to survive in pretty much any situaltion (SoD and last stand). additionally you can choose to combine in harms way with either to arms (ST boss fights mainly) for even more damage reduction, or with last stand (in fights with big aoe hits that can oneshot other group/raid members) to negate the drawback that you take the damage others take. plus they have an in combat rez that you went out of your way for to make unavailable for beorning tanks.
And that's only considering the yellow line traits on their own. captains get even far stronger if you trait into either red or blue - depending on the situation. traiting into red significantly buffs the entire groups dps and can let you maintain the red banner 100% of the time with a red captain in the group (which every raid group has) without sacrificing a dps spot. if you trait into blue on the other hand, your in combet rez will lose the induction and gain an additional target. additionally you will be able to maintain ~15-20k hps on each group member without effort, removing the need for healers in most 3-6 man content.
compare this to any other tanking line in the game (which btw makes up half of the roster of classes, yet only one works well atm), they are all squishier and have far less utility as tanks. even the arguably second best option, namely guardian, does not come close to captains, even tho tanking is the only thing they are designed for. guardians are theoretically speaking in a better spot than they actually are (that spot still being worse than captains tho). but the fact that 2/3 cooldowns are just a b/p/e buff, and all big hits just bypass that entirely, makes it really difficult for them to survive. redirect - while being stupidly strong in theory - is highly RNG based and is very unreliable because of that. all in all guardians would probably be tanky enough to compete with captains on that regard under the condition that the are constantly followed by 5-10 immortal mobs hitting them for 1 damage each with b/p/e-able skills. but since that condition is never given, they just fall flat in that regard.
and even with the recent buff to break ranks they still won't come close to captains on the group support/utility part. captains still have better/more consitant dps buffs and they don't even need to sacrifice damage reduction to use them.
tl;dr: Captains are way overtuned and they trivialize content. unless there are plans on making the other tanking classes as broken as captains (which i doubt cause that would be stupid), they need a number of serious nerfs in multiple aspects (survivability, group buffs and aoe heals while in tanking line) to even get the tanking meta into a somewhat decent shape.