So, just rewatched the movie. Dear me but it could have used at least another draft.
Anyhow, one of the things that really struck me was how absurdly close-ranged virtually all of Preston's fights were.
Deathdealer I: At Level 2, you gain the Cleave Basics feat. You also gain a trick.
Deathdealer (1h-ranged weapon trick): Your attack is made as a melee attack utilising your Wisdom modifier with a Reach equal to your starting action dice.
Deathdealer II: At Level 7, you gain the Cleave Mastery feat. Additionally, your Deathdealer trick may be applied to any personal ranged weapon, and the reach of the attack becomes equal to your class level.
I think I still prefer the current version of the ability, but that was the first thought that came to me given the discussion on the cleave chain elsewhere.