LLLLP Question

[Apatheist]

The problem with nuking the boss is that your priest will pull aggro, since the warlock taking damage will get interrupted and generate less threat then the priest.

If you spread them out and nuke the boss will bounce between whichever warlock currently has the highest threat. It doesn't matter if one of them gets interrupted. In fact, it will reduce the damage you take since the boss then has to switch targets and travel to another warlock when it exceeds the interrupted warlocks threat.

A priest will never cause as much threat as a warlock spamming shadowbolt no matter how much it heals.