BMI is not bullshit, but it is also not the best sole indicator for obesity.
It will give a rough guidline, and as a tool for measuring populations, is useful, for an individual, factors like total lean muscle mass, total body fat, bone structure, water content and weight distribution are very important.
Be that as it may, FieroLoki asked whether or not a 5 inch height difference would create a significant change in appearance given the same total body weight and general physical condition, and I say YES. 5 inches is a BIG number, and the shorter person will look much rounder. The exception would be a shorter person in very good physical condition carrying lots of lean muscle (which weighs more than fat).
I think Patty seems to have cut to the heart of the matter with her guess as to the reason for the question, in which case, get (and post) pics, so we can help you make a better decision than numbers alone.
ETA:
BMI calculator