LightCupcake, let’s get onto it. (Going from the most recent Gorefiend pulls)
First of all you are overhealing the encounter, 5 healers for Gorefiend was only useful when it was early on in progress and gear was very tight. Shamans are those who takes the biggest hit when overhealing content due to how tightly our output is linked to our mastery.
Riptide is being used as often as it should with only a slight deviation from the cooldown of the actual spell.
Healing Stream Totem could be used better, on average around 40 seconds between casts.
The distribution of spells other than that is very single target oriented. You shouldn’t be afraid to throw plenty of chain heals. Furthermore you should take advantage of how you position during feasts and cast healing rain more frequently, it should be down 100% of the time during feast of souls. A single time or not at all on Gorefiend is not good enough.
Try to use your class ability Gift of the Naaru don’t underestimate it’s potency, it can do upwards of 1% of your total healing if not more if used throughout a fight.
You barely cast Healing Tide Totem, this might be because you’re running a healer too many, simply rendering it useless because you’re never really in danger. This is resulting in a massive loss of potential healing. Make a nice rotation between healers and cast them in order, just line them up so you have a cooldown to take over when the previous one runs out and see if you have cooldowns to cover the entire phase.
Mana seems to be a non issue and I think this stems in not being super aggressive with Chain Heal, if upping the casts of those it might be needed to cast Elemental Blast more often (which admittedly is a bit low from the logs). You’re also not using any potions on the longer pulls, meaning that mana will disappear faster leading to the need of a potion. You could also go for the other option of using an intellect potion together with one of your cooldowns, although I wouldn’t recommend this for longer fights. Just be aggressive and adjust when you see that you’re oom.
Unleash Life, be careful not to use it just because you can see that it’s off cooldown. This spell in particular should only be used when you’re forced to relocate, the output in itself when stationary simply doesn’t compete with that of any other spell we have. I see some times where you use it for movement and sometimes where you pop it without moving.
Sometimes Spiritwalker’s Grace is not being used on encounters lasting longer than 5 minutes. Just make it a habit to use it whenever movement is required and then after having made a few pulls you’ll know where it is needed more than others and from that you can determine when it’s necessary and when it’s not. During Feast when cleansing the debuff is an ideal scenario to use it.
Experience will automatically make it better, so just keep at it and it will improve. Hope it was of any help and makes any sense.