A centaur's sperm

Male centaurs were naturally strong and resilient, females not so much. But there was a way for them to increase their strength and stamina - by having sex. The sperm was uniquely nutritious and the ejaculations were voluminous, it could also be absorbed through vagina. It had a similar effect on some female humanoids as well, elves included, but the male centaurs were not so eager to share their seed without mating and not many females possessed the powers comparable to that of the ring of shapeshifting which made the mating possible in the first place. This answer created another question - why did Korydos say that? Why would he be interested in the sorceress strength and stamina?