The Tiefling and the Hobgoblins

After defeating the gnome arcanist, the girls discovered some notes about his attempts to regain the lost knowledge of how the ancient tieflings had controlled the kruthiks. They also discovered that he was in contact with a member of an evil cabal of tieflings. They decided to track down the gnome's contact and stop his evil plans (mostly because they needed about one more big encounter's worth of xps to reach level 3).

Since I figured this was going to be a single encounter, I started with a tough 800xp budget. I knew I wanted my leader to be a tiefling heretic. I gave him some hobgoblin buddies, including a warcaster, just because I like hobgoblin warcasters.

So the encounter was:
1 tiefling heretic (level 6 artillery, 250 xp)
1 hobgoblin warcaster (level 3 controller, 150 xp)
3 hobgoblin soldiers (level 3 soldier, 450 xp each)
4 hobgoblin grunts (level 3 minion, 300 xp total)
Map: Forest Cliff Lair from Fantastic Locations: Dragondown Grotto

So I kinda went over budget and created a tough 1000xp fight. I tried to separate it by moving one soldier and two grunts outside the lair into the woods as guards, which would have changed it into an easy 225xp encounter and a tough 775xp one. So of course the PCs bluffed their way into being escorted by the outside guards into the depths of the cave and then got jumped by everything at once.

Everything went well for the bad guys for quite a few rounds. The soldiers got in formation and no one could seem to hit them. The heretic stayed back and repeatedly BBQ'd the ranger. The warcaster stayed back a bit and tried to slide PCs around, but he was hampered by his relatively short range powers and the wizard's flaming sphere. Eventually the warcaster dropped from constant fire damage, then the flaming sphere broke up the soldiers' formation. Meanwhile the ranger charged the tiefling and started chasing him all over. In the end they had to chase the teleporting heretic out into the woods and take him down at the far end of the map. They then tied him up, healed his wounds, and got ready to pump him for information.

Analysis:
Hobgoblin phalanx AC bonuses really shut the party down, while at the same time the tiefling heretic couldn't seem to miss the ranger. Every PC except the wizard was knocked to zero hp at least once, and the wizard was down to 4 hp when it was all over. With the beating they got, I'm not sure they're going to want to track down this tiefling's cabal...