(Author here.) That is incorrect. The difficult case is and the real benchmark is with unpredictable data. The low-entropy cases will be about as fast with both partitioning schemes.

This is only a smart part of the benchmarks I've run because I wanted to drive one point home within a limited space. I've run many tests on various data types and shapes, and Lomuto does better than Hoare on most. (E.g. its improvement on double is even larger than on integrals.)