The Beastmen have a tradition of sharing partners. Or rather, this isn't just a Beastman tradition. In ancient times, before the Realm of Order was firmly established, such customs were quite common.
The ultimate reason for this was immense pressure to survive. In an era without a stable Order and no reliable path to power, struggling tribes faced all sorts of natural and man-made disasters, Demon Beasts, and Spirit Monsters. To continue their existence by any means necessary, they had to fully leverage the power of bloodline succession.
If a tribe had a Powerhouse, whether homegrown or lured in from the outside, they had to squeeze every last drop of value out of them.
Relying on heaven and earth was not as good as relying on people. So, breed! Everyone, breed like your lives depend on it!
A powerful tribesman... especially a powerful male, if he could cast a wide net and sow his seed, leaving behind a few high-quality offspring, the entire tribe would be blessed for it.
