Best 4 person all caster/priest group

[Duik]

So the sham is torp tanking and either/both/all of the following... spot healing any chanter, malo, root, sunbeam, rotting 3-4 other mobs with epic, AndAnythingElseIHaventThoughtOf.

Chanelling must really be broken if we can be certain of not eating an interupt at an inopportune moment at some point.
With such a central and important group roll what with tanking and dpsing and healing and rooting etc being "ready" could pose a problem.

Is this what dsm is suggesting is the best?