Hart of Darkness

Reading through Remixed I noticed the recipe for the Hart of Darkness is different than the version on the total tiki app which calls for an ounce each of LH151 and LH80 whereas the original was just 1.5 oz of the 151. Mathematically they add up to roughly the same total proof so is there an advantage to making this one way over the other? Seems a strange modification to use a rum and then add a diluted version of the same rum to a drink.