yeah I am very sure you can justfy Rocky being a Con attack boxer useing this.Con -- I wear you down, counting on my endurance to outlast you. Blow after blow unrelenting until it gets through or you loose concentration for one second.
Not the hardest hitter but can keep at you.
I do agree though -- making these tied to ability scores is like making schools of magic tied to ability scores. Like your DCs and even ability to take X level spells are tied to high scores.