Welllll, I am not so sure about that article, but my repro prof used to say the more the stallion was bred, the more colts he would have. My mare has been the ONLY mare bred by the stallion 4 times, and I have 4 FILLIES!! Although, her mother had 3 fillies that were not "only children", so perhaps it is in the line.
I only want another foal by this one mare, and then I have no reason to breed anymore, so the point is moot (for me) anyway.
OP,Which breeding operation do you work for? Or are you just in school?