Unless the logs are bugged in which case this discussion is moot, your priest in an almost 10 minute attempt cast spirit shell
twice. That's a 1 minute cooldown ability, and at least on normal (and I'd imagine similar on heroic, perhaps even more so with the extra quilen there) the damage spikes are extremely predictable.
Not the paladin's fault the priest isn't using his abilities.
(not to mention on that fight, the top logs I see are mostly... monks).
[edit]
http://worldoflogs.com/reports/rt-2j...=17620&e=18271 - 34m SS + DA versus 26m IH
http://worldoflogs.com/reports/rt-uo...?s=8113&e=8725 - 34m SS + DA versus 25m IH
http://worldoflogs.com/reports/rt-bm...?s=4028&e=4643 - 32m SS + DA versus 28.6m, 25.4m IH
Yeah.... 10-11 minute kills, I see 6-9 uses of SS. So it's not a "can't use SS" thing.
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TL / DR: Not even claiming that we're "underpowered" or that others are "overpowered" - just saying that your suggestions are absurd.