I'm aware of the sizes (among other things) being incredibly vague. I've thrown a lot of systems together quickly, and I'm slowly trying to fine tune them as I go. I seem to be better at throwing in new stuff than fixing old stuff XD But I do come back around (See: the combat rework!)
Anthros would probably be around a size 10, for a comparison, and the sizes escalate quickly from there; perhaps 20 for horse-sized, 30 for elephantine, 40+ and you're getting into mythical beast sizes. 70+ is in the realm of "small" macros that could walk over mountain ranges in a few steps.
My original concept for all of the size statistics, was that bodysize was the primary size, and all other sizes were relative to bodysize. So a bodysize 2 with a cock size of 90 is a chihuaha with a dick the size of a baseball bat, while a bodysize 90 with a cocksize of 2 is... Mount Everest with the Washington Monument sticking out of it.