I think Sha of Doubt was made to sound a little more trivial than it is. There are multiple facets to this fight and the OP had a pretty good strat. I am just adding what I do to this thread: On the pull I run straight to the boss and start. You must immediately dispel both on the pull and after each add phase. Then, on the pull and after each add phase I spread out one at a time (no spread macro). The main thing about this fight is dispelling and killing the adds fast enough. On each adds phase I put everyone on follow and basically focus one at a time with some passive AOE.

So, my strat is group up, dispel then spread, nuke, group up, dispel then spread, nuke, etc.