No character storywise would want to help goblins, even an evil one (smart evil one).
Yeah, they need to make it more appealing. The character I had who sided with them only did it because the grove was already wiped out due to the sequence of events earlier. There was no reason to not give away the location and a lot of reasons to make possible new allies. I suppose there could be some argument for Minthara being persuasive but still not a good enough reason to side with them. She and the goblin leaders need more dialogue.
Do you think that the side with the goblins arc was intended as an alternative for players who had already destroyed the druid grove? Probably not, but it is interesting that the scenario happened to work in your playthrough.
I just realized that it's very strange that you don't get a choice in the first Goblin-grove encounter. Why aren't the mercenaries, Tieflings, Wyll and the goblins all yellow after the cut-scene. What if you just want to chill out and watch it play out, or decide that helping a goblin raiding party is your new favorite idea. If the goblins had actually attacked the party or insinuated as much in the cut-scene it would, of course, be a non issue.
