Do you mean for statistically average humans, or for men and women participating in the same activity?
Both. I mean that the comparison would hold true whether we were comparing women who engage in an atheletic activity at a high level with men who played the sport at a high level, or if we compared women who didn't engage in sports with men who also didn't. Thus, it doesn't matter if we were comparing tennis players to tennis players, office workers to office workers, boxers to boxers, or linemen playing football (the gridiron variaty) to linemen playing football. The gender differences would remain about the same, or even be greater than what I outlined. Though the extent that they are greater in some sectors is probably cultural/social rather than genetic.
After here your math just gets wierd. First you make an assumption of 10 STR as average male strength, then having made that assumption you immediately invalidate it by making a different assumption about male average strength. You also can't seem to subtract 8 from 11 and get 3, and that even to get to the 8.5 vs. 11.5 comparison you had to make selections that involved rounding up from 8 favorably for the female and rounding down from 12 disfavorably for the male average. Then after subtracting 8 from 11 to get 2, you then rounded mentally down again by claiming that it was mostly lifting capacity rather than raw power which was effected (which is again exactly backwards of reality because its fast muscle and not slow muscle that makes up the bulk of the difference between the two sexes) to get to 1, which you then mentally handwaved again down to 0 because a -1 penalty was trivial.
There is a comedy reutine in there somewhere.
You had to jump through a lot of hoops to get roughly a -4 strength modifier down to -1 or maybe zero. Cognitive dissonance much?
I would just like to point out that not even halflings (weighing 30 lbs) are assumed be be only 2/3rds of the strength of human (males) which is itself terribly unrealistic, but there it is. That's the reality. If you don't like that reality to the extent that because you have a little fantasy world where everyone is valued according to how much they can bench press and how hard they can throw a punch, you have to make women in that fantasy world equally strong as men then fine. But don't mistake that for comfort with the feminine, and claim that somehow if the world doesn't indulge this fantasy (which apparently extends into how you must view the real world) then those not so indulging are morally deficient, sexist, stuck in the past, or whatever.