Its called "A good rule of thumb" not the law. the more matched a tire is to a rim the more stable it is. A narrow wheel will allow your tire to roll under easier. I used to run 35/12.5-15 on a 10 inch wheel. I would air down to 2-3 psi and never lost a bead. the outlaw II has an internal bead lock built into it. its a small ridge that runs the circumference just inside where the bead mounts. just because you can mount a 44 on a hummer rim does not mean its the proper set up. Your tire is held on your rim with the same amount of pressure regardless if its a 8 or 10 inch wheel. think about it 10 psi is 10 psi

thats 10 pounds of pressure on every square inch of tire. there is also a larger volume of air in a wider rim setup requiring slightly less pressure to hold up the same weight. rim width is a factor in losing beads when you go too wide with the rim and the tire itself is pulling away from the bead. Find a local tire shop that does nothing but tire and pick there brains. not somewhere that also does service, a true tire shop, they will point you in the right direction. sanddawgk5 is letting his opinion get in the way of sound advice.