The whole premise of the evil path is wrong. It's going out your way to do bad at potentially great expense. It's just full Chaotic Stupid. The obvious hook for an evil path would have been Kagha, siding with her because her way of defending the grove didn't involve you fighting your way through a goblin camp. And for two of the leaders in the goblin camp there is no dialogue options that produce a result significantly different to just attacking them on the regular path.
