The Hobgoblins are Legion

The last two surviving goblinoids fled from the party's wrath, racing up the trail into a thicket of pines atop the ridge. As they run, you hear their cries of loathing and promises of revenge from the "big boys." You are able to easily pursue them due to their careless retreat and constant snarling remarks. After several hundred yards you notice the trees thinning as the path of retreat nears the edge of the thicket and a bare wall of rock looms up a hundred feet away.

At this point, the loud shrieks of escaping voices are joined by the harsh commands of several more voices. Breaking the edge of the wood, you can see that the face of the rock wall is pocked with three small cave openings, and one large one at the base of the cliff.
The two creatures you have been following can just be seen disappearing into the large cave mouth. In the "courtyard" there are 6 hulking brutes... hobgoblins. They are rising and forming ranks (History/Nature DC12 to know hobgoblins pride themselves on their martial acumen, and that some can pose a challenge for their tactics and brutality). These are led by a Hobgoblin Warlord of somewhat lesser ability.
Three of them are hobgoblins, two are hobgoblin captains, and the hobgoblin warlord. There are also six goblins inside the caves, two bugbears, and two more hobgoblins. The goblins will scurry to the three cave openings up the cliff, and the remaining hobgoblins and bugbears will move to join the battle formation in the courtyard.
The hobgoblin warlord believes he is a great general, and will line his men up and direct their actions, calling for a forward assault and a flanking operation from the captains. His insistence on discipline and holding their positions will undermine their effectiveness. The goblins will set themselves up to fire down on the party.
The cliff can be scaled by rolling a successful Athletics check (DC12), and moving at half speed. The caves are located 10, 20 and 30 feet above the ground. Another option would be to move past the ordered legion outside and directly inside the cave. Doing this will bring them face to face with the bugbears and hobgoblins inside the cave. This will give the warlord great delight as he directs his force to turn about and apply a pincer attack in consort with the others inside the cave. Once this occurs, his careful planning will come apart, and confusion will reign. Otherwise, the hobgoblins will be sluggish and uncertain about what to do without instruction.
This should be a fun battle, with the hobgoblins behaving in erratic and unpredictable fashion. Once they are defeated, a search of the caves will reveal some nice treasure, as well as some of the goods stolen from Prudence' cabin.