Aye.
But sadly, that doesn't work out well. As in order to free Halsin, you need to kill all the leaders (Or at the very least, incapacitate Minthara).
Are you sure about this ? I never actually killed Halsin, but the ususal way I handle this part of the game, is to go to the worg pens after meeting priestess Gut (and Volo, the Zhentarim, Abdirak etc....) anyway, avoiding Minthy and Razglin entirely, then free Halsin from the cage and slay the goblins there. Halsin will then examine me and tell me about Moonrise towers on the spot, advising me that is the place to go to and find out how to remove the tadpole. Then I tell him to stay put in the pens, and I go to Minthara to set the trap for her. Razglin will be handled when I go back to the camp after the grove was saved. When the grove is saved, Halsin somehow got away from the camp and enters the grove all by himself. So, it would seem possible for the party to kill Halsin after he has diagnosed us in the worg pens area, and then side with Minthara. I'll try that out whenever I get back to that place.
Which is part of why "Evil route sucks" is a thing.
Had you been able to infiltrate the goblin camp and free Halsin, he could give you the information about the tadpole and direct you to Moonrise.
With then the choice being about killing the Goblin leaders and getting Halsin as a guide through the Shadow-cursed Lands. Or killing the Tieflings and getting Minthara plus a fancy pixie lantern to take you directly to Moonrise.
Throw in the tadpoles themselves being exclusive to the Evil path and now you have a situation where both good and evil characters rescue Halsin because that's the primary thing you're told to do and the best source of information at the time. But then a choice is made. One is a good path that gets the Grove and Tieflings as allies (And will lead to Last Light Inn as a friendly hub). The other is an evil path that will get you more power and take you directly to the source you want to investigate (Plus it could set you up to obtain more tadpoles by doing errands for people in Moonrise enabling more power)
This could, in theory, also open up additional avenues of how the routes play out.
An evil character could still side with Halsin because remaining allies with the people who seem to actually know about the existence of the tadpoles can be a solid strategy.
While a good character could try and convince Minthara to not attack the Grove and do something else to ally with her as getting direct passage to Moonrise is a logical plan.
Thus creating some depth to choices, where you think about how you deal with the information you're provided. As opposed to walking a specific one-dimensional path.
Yes, it would have been nice to have all these options to explore. However I think the guardian plays their role here also. They seem to decide to shield Minthara (or any other tadpoled creature) from the elder brain like they wish. (cf. the reluctance to shield Minsc) , so the plan should also be in the guardian's interest.
