While a bit more detail would be helpful, I can offer some general advice, at least.
The battle at the twisted tree, focus on the ancient ones (I forget what they're called) first, because they spawn the younger ones on their turn and letting them live too long can easily get you overwhelmed.
As to the hobgoblin boss, I usually save that battle for last (or just before Minthara but after the rest of the fort is cleared out), so I'm not dealing with any goblins outside his area. Also, I prefer to fight from the rafters (or ramparts, as everyone else calls them) there, both because of the high ground advantage and it makes it difficult for the enemy to get at me. There is only one way for them to get up there, the metal ladder to the hobgoblin's right (if viewing him from behind). Also, even since the last patch (not hotfix), I've not had too much trouble pushing him around, though I am working from the high ground (and using Lae'zel's pushing attack)
