I have a noticeable difference between them. While Gero suppressing 18 compared to 17 (due to making her not disobedient like 17) wouldn't make sense if it was by a slight amount, there's that line from 16, in which weighted Kamiccolo rivals both androids, indicating that there's not a huge difference between them. I generally have 18 as a distant rival (or maybe as not even a rival, depending how one interpret that type of gap), with weighted Kamiccolo in the middle of them:
Android 18 : 87.5
W. Kamiccolo : 90
Android 17 : 100