Seems like a reasonable scale.
I don't know why people don't talk about girth as much. A really thick cock is an exciting thing to see and use for pleasure. My understanding that some or even many women prefer the extra sensation of a thicker penis. I know I like the look of a thick cock.
How I view the various sizes:
XS....I'll suck that.
S.....I'll suck that.
M.....I'll suck that.
L.....I'll suck that.
XL....I'll suck that*.
XXL...I'll suck that**.
* At least as much as I can fit.

