what am i doing wrong?

[Anubis_Nephthys]

While i agree that the other tank in this scenario should have solid aggro (so this SHOULDN'T ever happen), you can make up for another tank.
Perhaps the long animation/time to go off on RoH is the problem. In a tank swap scenario, it should always be on a tank once the fight has gotten underway.
Here's some tips that PLDs can use for snap aggro. (These are mostly useful for snap aggro on unclaimed/new mobs, but they still help.)
1.) Que up a Savage Blade instead of a RoH. Savage Blade goes off significantly faster than RoH. This way you get snap aggro very quickly, and you have a big daddy RoH right after.
2.) Use weave-ins on tank swaps. Spirits Within and CoS are my friends
3.) Perhaps even use Fight or Flight if you have to.
I hope you hadn't heard/thought of at least something here! Happy Tanking!

[FriendlyUncle]

While i agree that the other tank in this scenario should have solid aggro (so this SHOULDN'T ever happen), you can make up for another tank.
Perhaps the long animation/time to go off on RoH is the problem. In a tank swap scenario, it should always be on a tank once the fight has gotten underway.
Here's some tips that PLDs can use for snap aggro. (These are mostly useful for snap aggro on unclaimed/new mobs, but they still help.)
1.) Que up a Savage Blade instead of a RoH. Savage Blade goes off significantly faster than RoH. This way you get snap aggro very quickly, and you have a big daddy RoH right after.
2.) Use weave-ins on tank swaps. Spirits Within and CoS are my friends
3.) Perhaps even use Fight or Flight if you have to.
I hope you hadn't heard/thought of at least something here! Happy Tanking!

What he said. RoH can be good but if you have some ball crushing DPS, Savage Blade will do well enough. I tend to do what he suggests, I will prep my combo up. On something like Garuda if I am OT I will usually just start using only Fast Blade > Savage until she spawns Chir and Sup. Sort of a lottery there but it can work, hit her with your prepped combo into CoS or SW while running off and can Shield Lob for good measure.

Beyond that first phase, again. Do as he would say. :P The spawns are predictable, you know shes gonna summon right after spiny. Pop Fight or Flight, SL my target, followed up with a CoS or SW while moving away in position.