Just reading through some old posts for tips and came across this.
I think that women scale by age on this. A 50 year old who didn't marry could have 13 partners by the scaling logic and be category 3 and be sweet as an angel.
There's also time factors. Length between partners or wild old days. I think phases come into it here.
That said, I have done 1 in the first category, at least 1 in category 2 and 1 category 3 and most certainly 1 category 4. As said above the 3 made my life difficult, the 1 awesome, the 2 interesting and the 4 was a adventure. Hence, the characteristics (mixing and matching) are spot on!
P.s. I miss category 4 girls. Man, they are fun!