DPS activity is scary how low it is. And it gets worse the longer the fight progresses which is counter intuitive (if I have more things to attack, I'm significantly less likely to be inactive).
1. Ignore twilight barrage (the small damage on boat from drakes). Given that you're taking a lot of damage from it that tells me your DPS is going out of their way to stand in it. Guess what, this is contributing to their inactivity.
2. If you have to move, keep attacking. Even if you're attacking the wrong target. It's better to have the wrong target die earlier than it is to not do anything at all. And of your four ranged DPS, have any realized yet they can attack the drakes when the fly over the boat to drop off the melee mobs? I've done 2-3 attacks on each of them before even switching to melee at the start. It's harder to do this on the later spawns but still possible. There is no excuse to not do it on the first wave (if you have nothing else to attack, attack what you can as soon as you can).
When to move?
1. When twilight onslaught is cast all DPS, healers, and inactive tank (tanks actively tanking melee mobs should stay out to not cleave people) move into it. If a sapper is out stun/slow it and ranged DPS should be able to kill it with instant casts or larger casts once they are done moving (most of your DPS is ranged).
2. After twilight onslaught hits everyone spreads back out again. Melee returns to either a sapper or the melee mobs while ranged fans out around the boat to minimize the number of targets that are hit by a charge.
3. Ranged and Healers: Move to avoid twilight barrage and charge when possible. Melee: Move to maximize DPS activity (i.e. if both mobs charge away from the tank you don't need to wait for it to get back to the tank). Tanks: Minimize movement of the adds so that DPS has higher activity. Inactive Tank: Move into any twilight barrage or twilight onslaught until more melee mobs spawn for you to tank.
Strategy basic differences on 10 man from 25 man...
Many raids in 10 man will opt for a single active tank at a time instead of switching which mob you are tanking each wave like 25 man. Using both tanks all the time caters better to a group with more healers so that they can dedicate more healing to each of them. In a 10 man set up where you only have two healers, minimizing the number of targets that require healing is actually better. By having one tank pick up both of the adds in each wave you also trivialize making sure both mobs can be cleaved, without them cleaving other players. You will have both debuffs stacking on you at once, but when the next wave spawns the other tank picks them up and during that time your debuffs fall off. One tank picks up first and third set of adds. The other picks up second and the boss when he comes in. When a tank doesn't have anything to tank, they are free to DPS and they are also free to stand in any twilight barrage or twilight onslaught. While the tank is actively tanking they try to keep the mobs relatively centered on the boat(closer to the front so melee can swap to sappers quickly) so that people can spread out around them minimizing the number of people potentially hit by a charge.
"In anything, if you want to go from just a beginner to a pro, you need a montage." /w TankSpot WTB Montage for Raiders.