All else being equal, more reach means more likely to come out the winner, you only need one poke. But all is not equal, longer blade is also heavier and harder to maneuver where it needs to go. That's why length of blade depends on quality of steel, with better quality you can make it longer without compromising weight and strength too much. But if you don't have the quality you end up with a slow club that just isn't that good to use. Romans couldn't have made something like a rapier if they wanted to, their metallurgy wasn't up to snuff.