By the way, and I suppose it’s a bit irrelevant as you’re past it now and anyway I’m no expert on combat tactics.
But the grove gate fight is pretty easy if you bring your party onto the bluff that overlooks the entrance and trigger the fight there, rather than come through the gully to the gate. If you’re up there, your squishier ranged characters are kept away from the harder hitting goblins and have the benefit of high ground, and your melee characters can help pick off the lower HP back lines of the goblin party while the goblin melee fighters concentrate on Aradin and friends. You can move your party forward to help finish off any of the goblin front line still alive after the booyahg and archers are dead.
In early patches, taking this approach would often lead to one or more deaths in Aradin’s party unless you helped them, but I think they’ve got better at staying alive since.
With a lot of the fights, there’s something similar you can do to help the environment favour you.