Master4thWall
I do not think you have a way to use it after all you are going to kill about 400 500 of his people (that calculation is before they give up I guess, maybe you kill less) and at least from how they showed it in the original series he does not seem the guy who forgives that kind of behavior, plus your MC is not one to let someone who can create problems alive and Gan Fall is, so my advice is to kill him, but I hope at the same time that you get out with something different since I like to see the imagination of others not my own ideas. Thanks for the chapter !!
gan fall might see that amon is stronger and that the reason they have no peace is because shandians don't have enough food and want their land back. gan fall might agree to join amon if it's to save the civilians of upper yard? maybe amon already put traps and bombs in key locations to threaten him? just putting a scenario out there