I started running the Shroud right at the tail end of Mod 6 (I recently completed my 60th run on my main about a week back) but I have some questions about the sudden shift in strategy which occurred at the release of Mod 9.
The "old" strategy (for those who are unfamiliar or have forgotten about it) is to keep the 4 named monster separated from the very beginning of this fight. In most situations, you have 1 DPS and 1 healer fight the Outsider (Devil, Orthon, or Cat) in the "west cubby," put the 2 humanoids (gnoll, troll, orc, kobold, trog) into the southeast corner with 3 blockers and a Wall of Fire, and put the elemental in the Northeast corner with either (a) a self-healing caster or (b) evasion DPS and a healer. Each of the 3 teams preps their monster to ~10% hp, then kills them all within ~5 seconds of each other. The caster who cast Wall of Fire on the southeast corner (also referred to as "The Wall") is usually waiting at the crystal, since they are not required to actually be near the monsters that are cooking.
The "new" strategy is to pull all 4 monsters into the south central area (near the "buffing rock"), and, as a group, DPS all monsters down to 0% health. Once the monsters no longer have a health bar, the people holding aggro on these monsters split apart from the main group and deal a few more additional points of damage to each monster, killing them. A caster waits at the crystal.
Here is my question: Why did the strategy shift from splitting before killing to killing as a group, then splitting?
Out of the last 10 Shrouds I have been in, the "new" strategy has been used and not a single Shroud has had a perfect (meaning no "repull") p2. Something always seems to happen--one person gets the aggro from more than 1 creature, making the syncronized killing virtually impossible, or the clerics run out of mana because the fire elemental is nuking the entire group, the Gnoll plants a blade barrier (which people promptly start running through) while he proceeds to start spamming Dispel magic on the group, or the monsters show up at different times and someone kills a monster prematurely, etc. These problems rarely occur when the monsters are split up beforehand, yet this new way remains the most widely accepted and practiced method of completing p2 of the Shroud. What is the advantage of mass-pulling that I am failing to see?