I disagree.
I would argue that the balance is heavily in Towns favor to begin with. Adding more would only increase it.
Here is my bad bad reasoning:
If you ever checked the wiki website from where Gyrl took the setup - you surely noticed that there the statistics usually show Scums winning most games even in
heavy-town-favored setups. This setup Town has higher win %, so I guess the setup is insanely heavily town favored.
If you think about this general strategy of the setup:
I think you too would come to the same conclusion as me - increasing the number of guards would drastically imrpove Towns chances. Feels like exponentially, not linearly.
I would guess that Jack thought something like that?
Either that or he has some political agreement with other websites to not change the setups he copies from them.