The biggest potential problem I see you commonly running into with so many melee is horrible pathing through chokepoints. You can lessen the impact of this by techniques such as these:
a) Try to get enemies to come out from the chokepoints when you can. Having just a bit of Stealth can be useful here, as you can set a trap in a doorway, send your mechanic back a bit, then unstealth to start combat and wait for enemies to come through the door. I personally haven't found a need for Survival at all, or for more than 3 Athletics to reduce the combat fatigue gain, so what I typically do is get 3 Athletics first, then raise either Lore or Mechanics always a few points ahead of Stealth, and you can end up with pretty high Stealth on top of 10 Lore or Mechanics. That's my personal preference, just an idea.
b) You might want one barbarian to be at least slightly tanky, and give the other a reach weapon (Tall Grass tends to be a favorite). Even if you don't want any using reach or ranged as primary weapons, I'd recommend giving them all either a reach or ranged weapon to switch to for when you end up in a choke point with no clean way to fix the situation. And you are pretty much guaranteed to run into this at least from time to time, even if you play carefully.
Edit: The other thing I wanted to say is about your wizard wearing plate. Personally, I have tried the same tough fights (namely, ones with lots of Shades/Shadows) on PoTD with two strategies. First, I tried dressing all my characters in plate and focus firing the tougher enemies (Shades) who spawn the Shadows and whose Shadows die when they die. This strategy was recommended to me, and it sounds logical. However, what I found is that the non-tanks who were getting hit by teleporting Shadows still died, albeit much more slowly, through loss of Health and not Endurance, which you can't avoid no matter how much healing you have. Meanwhile, the plate and interruption reduced my DPS so much that I just couldn't bring down the Shades even focus firing them.
I tried the same fight with my ranged wearing their normal robes, focus firing the lower DR Shadows first, and switching to whichever one teleported onto my ranged members, and this worked much better. The fight ended up going much more quickly and cleanly, and I ultimately prevailed. So, personally, I prefer focusing on DPS or throughput for ranged. Even with a control wizard, you want his status effects applied as fast as possible. Wizards thankfully have some defensive spells you can keep at the ready for when they get targeted, so you can have some defense when you need it without focusing on it at the expense of CC/debuffs, which is indirect DPS for your party and which you want active as soon as possible.
Edited by Nobear, 02 July 2015 - 09:33 AM.