Most people do not have similar widths. Width varies greatly.

5 1/2 and over is good for me. Width is important too. I don't like noodle dicks, but I also dont like super thick ones. I was with a guy with a fucking THICK dick and i could hardly suck it without it hitting my teeth everywhere and I would not want that thing attempting to shove its way into my ass. It was weird looking. *shudder*