I play SCH today and pvp a fair few fight solo, half made group and premade group. I only pvp like 21/22 fight today, and i win like 11/21or22 fight. the sleep is really annoying but once you figure out a way to deal with it is pretty simple.

Some SCH said all they use is lushrate true i use it a fair few times but i did use physick alot too. and you manage to keep team off sleep/stun they will pretty ignore you. by then your team would have pretty much won the fight. I say if the enemy team can't kill healer in 20 second ish is pointless, for SCH that is. i mean you got 6 uninterrupted healing is pretty hard to kill. (surecast twice, swiftcast, lushrate) and if you get the caster pvp spell that is 5 more additional heal for rank 0.

leech have 1second cast times kinda hard to interrupt. ofcourse it also depend on your team as well. and learn to kite the melee DPS and use miasma II. which allow your dps and tank to kill their dps, and hopefully win you the match.