Hey! Welcome to the community!
Here’s an old thread about Fable 2 and Horizon: Horizon | How to Mod Your Fable 2 Strength, Skill and More!.
The first post lists all of the capabilities of Horizon for use with Fable 2. Horizon is pretty much used to modify numerical based elements in games (ammo, health, items, character level, etc.) and not so much character traits like the one you are describing. A glitch or exploit to allow punching during normal gameplay will likely be your best bet and Google is your friend with that.
Sorry to be a downer, but I hope I was of some assistance 