I think you may have some model numbers and/or benchmark numbers mixed up. I don't see the 6700K or 6700T in the charts in this Ars article.
I see a 7600K with the 637 score, but that lacks hyperthreading and has 25% less L3 cache compared to the 6700T, so it makes sense that the 17% frequency advantage is mostly balanced out (there's little IPC difference between Kaby Lake and Skylake).
Edit: Actually the frequency difference may be a bit off from 17%, that was based off the max single core turbo frequencies. I don't know what the all core turbos are.
I see a 7600K with the 637 score, but that lacks hyperthreading and has 25% less L3 cache compared to the 6700T, so it makes sense that the 17% frequency advantage is mostly balanced out (there's little IPC difference between Kaby Lake and Skylake).
You don't have notebookcheck's numbers matched up with the right CPUs either: https://www.notebookcheck.net/Mobile-Processors-Benchmark-Li...
To be fair, Ars has the i5-7600K listed as an i7, and Notebookcheck has the cache sizes wrong: http://ark.intel.com/compare/88200,97129,97144,88195
So there is plenty of confusion to go around.
Edit: Actually the frequency difference may be a bit off from 17%, that was based off the max single core turbo frequencies. I don't know what the all core turbos are.