The first thing that you should recognize about this fight is a large portion of it's complexity comes down to RNG. Where your firewalls and void zones spawn can make this fight simple (as you can see in the video) or much more difficult. Other luck factors that contribute, but not nearly as much, are the timing of both Sartharion and Drake breaths. Generally this comes in the form of Sartharion breath + melee on the MT or double drake breath on the drake tank. We had very little problems with this, but it happens.
Our strategy revolves around a Holy Paladin and effectively using Beacon of Light (Beacon) and Judgment of Light. We use three tanks, two healers, and 5 synergized DPS for our setup, one of which should be a shaman for Bloodlust/Heroism. We ignore portals, healing through any Twlight Torment damage until all drakes are down.
Our MT tanks Sarth on the front-left side of the island, while our OT tanks drakes on the middle-left side of the island. This is the most important positioning caveat of the entire strategy; The two tanks must remain in Beacon distance (40 yards). We call walls inside and out, depending on where the gap(s) are located. On inside walls (from the right side), the OT does not move, while the MT swings to the front of the island. On outside walls (from the left side), both tanks move together to catch the front gap. Between the Holy Paladin Hand of Sacrifice/Bubble and the Feral Druid's cooldowns/resists, we have the large breaths covered.
Our add tank can DPS the single adds with no help until the whelps pop when he begins to simply hold them, optimally dragging them into the incidental AoE created by DPS on the drakes (Divine Storm for example). Other than the adds, the add tank's only other responsibility is to grab the third drake and carry him into taunt range for the drake tank. We do this to maximize the DPS time on drakes, allowing us to push through the likes of Twilight Torment.
We also perform a tank switch at some point past the "danger zone" of big breaths to help lessen the melee damage to the MT. In this video, the add tank switches with the MT after Shadron is dead. The MT's gearing choices are built around Stam/Resist and thus he takes significantly more melee damage from Sartharion's normal attack, thus the switch. We have swapped the OT and MT after all drakes are dead as well.
The Holy Paladin is responsible for the MT and OT only. We have used (thus far) both a Resto Shaman and Holy Priest as our second healer with the responsibility for the remaining raid members successfully. We also have the Holy Paladin judge Light on the current drake, which significantly helps with Twilight Torment damage.
We have successfully used both a melee and caster group to defeat the encounter. This video is of our Melee group. We burn Bloodlust/Heroism on Tenebron, then continue DPSing the drakes in order until they are all down. After drakes, we clean up the portals, then finish Sartharion.
As you can see, we broke our own synergy rule here with the Elemental Shaman, however the benefit of totems for melee and Bloodlust/Heroism far outweighed the negatives.
This was by far the easiest Sarth 3D 10 attempt I have ever seen due to the insane luck with all but 1 firewall. The video is from my (Prot Paladin OT) perspective, but you can see nearly the entire island at all times due to my zoom. (Yes, I missed my Avenger's Shield, however the add tank luckily was in the vicinity and got initial aggro.)
Nice video & soundtrack, thanks for putting it up, I enjoyed watching it.
yeah the reasons why I love this fight so much now is because of the random nature of the wall directions, void zones, and the timing & size of the big breaths. 10 man feels to us like it could never actually be on farm - its just too sensitive to all these factors.