Ok, took a couple snapshots of truck with w2w stainless steps. I did not have my trusty measuring tape with me but as for clearance the fuel tank bottom front edge hangs down about 1/2" LOWER than the bottom of the actual tube of the side steps, probably almost exactly the same level as the bottom edge of the mounting bracket (best as I could eyeball it). So, while technically these steps do lower the ground clearance at the midpoint, IF you drag these steps on something then you better stop if you want to keep your fuel tank intact, so the ground clearance is technically a non-issue methinks.
There is a photo with a closeup of the endcap next to the molded splashguards. 1 inch off the tube made a perfect gap.