It happens in every VFW hall and every online forum: "He got 70% for the same back condition and I only got 30%." I understand the frustration, but that comparison will lead you in the wrong direction every time.
Ratings are about evidence, not diagnosis
Two veterans with the "same" condition can have completely different files. Ratings under 38 CFR Part 4 are driven by measured severity — range of motion, frequency of flare-ups, functional loss — not by the name of the condition. His 70% reflects his evidence. Your 30% reflects yours.
Fix your file, not the comparison
Instead of asking why his number is higher, ask what his file has that yours does not: current measurements, a nexus opinion, documented flare-ups. Then build those into your own claim. The path to a higher rating runs through your evidence, not someone else's award letter.