Whats the deal with that last mob in Stronghold?

Assault on the Stronghold is one of those "short but sweet" missions where you get to kill a crap ton of stuff in a relatively short window of time. It (along with Warband) was one of my favorite missions for a while but all of a sudden after about half a dozen runs or so (this is filling out books for HM rep) it seemed like the spawns were different, or my group was practicing different aggro habits. Warband gave me no trouble at all for the first few runs, but all of a sudden there was this ridiculous aggro crisis coming out of a tunnel on level 2 that I could only fight through about a third of the time.

Eventually I cut warband out of my run entirely (it's long anyway) but kept Assault on account of its brevity. But not long after I adopted this policy, it seemed like I was developing some of the same problems with this mission. The first part is easy enough, but between Hierophant "Coward Mode" Burntsoul and that last mob on the left, my party almost always wipes and since I'm h/hing with Sab's build, I may as well resign once I run out of minions. I've taken to leaving a few Charr alive behind me for spare minions in case of a wipe, but no single strategy has proven reliable. I've beaten it about 20 times, but I'd prefer not to think about how many times I've tried. It didn't strike me as a particularly challenging mission at first, but it seems like something's different now.

So here's what I do: Once Burntsoul starts jabbering about Destroyers I (a Divert Hex prot) call the nearest Charr Firereigner and sic my party on him. I strip the nearest charr mob (on the right) of all the damage I can and then I focus on Destroyer melee creatures. No problem. I progress right and take out the remaining Charr mob (usually a couple elite guards and a seeker) while Burntsoul and the mobs on the other side run around like they're using "Charge!" but they're not.

After that my priority becomes the destruction of Burntsoul. I flag Master of Whispers (my Jagged MM) a short ways back so his minions don't rush in and aggro all remaining Charr. Frequently Burntsoul's remaining guards are still in "Coward Mode" where they run back and forth and I have to break aggro to make sure we don't bite off more than we can chew. But here's the problem: Even assuming the above tactics work as intended, casualties are almost impossible to avoid and I almost never have more than 5 or 6 minions going after the last mob. It always has either 2 Wardkeepers or 2 Avengers, and I think I have an easier time when it's the Wardkeepers but I'm not sure yet (since I haven't started paying attention to the spawn until recently). So if anyone else out there h/h's this (especially if its with Sab's build) how do you deal with that last mob?

Since Hex protection is (IMO) the Achilles' Heel of Sab's build, I run DH Prot and it works very well so I'm unlikely to make drastic changes to my skills (which seem to work against every other Charr mob in the game just fine). My Heroes are Heal, Prot, Fire, and Interrupt. One of its few weaknesses (leaving aside over-aggro) is that it doesn't have that much damage before minions get rolling, since Cynn and the archer are about all I have until that happens.

Hex eater signet or more interrupts would probably help. Technobabble pve skill can cause dazed to non casters.

I suppose since there's always the two casters in that last mob a zero-spec Cry of Frustration on my N/Me would probably be boss. Hopefully it makes some kind of difference

if you let the destroyers and charr fight there is usually on the boss group and 1 or two others of charr or destroyer left. Pull the groups back separately so they don't agro the boss group that runs around a lot. Don't think I've ever not completed the quest once at that last part.

The outcome of the fight is always the same for me (not sure if that's how its supposed to be or what, but the results never vary). The mob I'm complaining about always survives the Destroyer assault intact; in fact both mobs on the left usually make out pretty well.

Aren't you hurrying it up a bit too much? The useual tactic is to wait before the stairs and let the Char and Destroyers kill each other, than cleanup whats left of them.
When I'm in a hurry I skip this and start fighting the right group, than move counter clockwise around the hostages. Actually this part should not be hard with Sab's build but as an alternative you could replace Xandra by Koss as a Wa/Ne with any kind of Tank build, and with [skill]plague signet[/skill] equiped. Be sure to add a protector hench in this build.

This mostly works well. But sometimes I have problems with the narrow passage before the final area; the 2 groups of Charr left and right can be pretty tough when aggroing goes wrong

Letting the Destroyers and Charr fight it out will not solve the problem I'm having. The outcome is always the same and the mob I can't seem to beat is always intact and I save it for last. I already use a Protector hench and I'm a prot monk anyway so that's not a problem.

But conditions haven't really been that much of a problem, so I don't see what Plague Signet will solve. I'm not opposed to the idea of swapping out my SS for something else, but I have enough trouble making sure my minions don't break aggro--the last thing I want to micromanage is a melee hench (I haven't used one since Prophecies).

Oops, my bad. You mentioned hex protection and my Koss build is meant to attract hexes to him, so he can spread them back. I should have mentioned the combo he uses: [skill]poisoned heart[/skill][skill]plague signet[/skill]. To increase effectiveness I give the other heroes this one: [skill]signet of toxic shock[/skill]. I think the combination Necro/Assassin has much potential. Especially if combined with lifestealing skills and [skill]animate vampiric horror[/skill] to keep lifepoints up.

I support the idea that you're rushing things. After Burntsoul starts talking about the destroyers, pull back a little. Flag your party back so it's back a bit in the narrow passage leading up to the steps. Then, all it takes is you walking up the steps to cause the destroyers to engage the charr. just be careful of your own aggro. I've had multiple outcomes with this, including one case where the destroyers actuall killed Burntsoul for me. Once you finish off the remaining destroyers or charr that were fighting while you took a break near the steps, you win. ^ ^

I'll try that tonight, but to be honest I still don't think that waiting will solve my problem. Here's why:

When you approach the last area of Stronghold, there are (IIRC) five mobs of Charr: lower left, lower right, top left, top right, and Burntsoul. Lower left usually gets mauled and there's typically only 1-3 Charr left in it by the time the Destroyers are gone. Lower right gets sandwiched between myself and the Destroyers and is quickly dispatched; but to be honest I haven't had any problems at all with the Destroyer phase of the fight. People tell me to wait and that's fine (I'll try anything once) but I'm not having problems with the Destroyer + Charr mobs, I'm having trouble mopping up what they leave behind. The "Upper Left" mob (the one this thread is complaining about) has always survived the Destroyer attack in each of my twenty or so runs. Upper Right and Burntsoul never have healers so there's usually no difficulty there. But what I'm having a hard time wondering is: How on earth can my team beat dual monk mobs, yet we are somehow outhealed by two Avengers when we have barbs + minions + ss bearing down on them the whole time? It doesn't make much sense to me. I mean, Avengers have okay bars, but there's nothing there that strikes me as being particularly inimical to my build and I have absolutely no problem with them anywhere else in the game. Its weird.