Sheep is fine exactly as it is. People dying to it are just whining because they got punished for being out of position. They need to revert the nerf to Misery and probably make Aquaveil function like Warden's Paean, where it still provides an effect shield even if cast ahead of time. Cleansing is very hard with high GCD and very low tickrate and it makes Aquaveil pretty terrible unless you're leaving tons of empty GCDs to be ready to snipe something (and hope it's the right thing!)

Because right now, AST is undeniably the best healer and SCH is very close behind it. SGE is just a DPS with the wrong hue.