Well no. While this should definately be implemented for random/lesser courtiers I completely disagree with this being a reality for real historical monarchs.
Again, look at Henry the Younger, Geoffrey of Brittany and Richard the Lionheart, or Louis the Lion, son of King Philippe of France. Even the male children of James I of Aragon. All of them were addicted to tournaments, and fought them personally.
It is true that first born heirs were married when they were young. Henry the Young King was wandering with his household knights and the fighters of his private tournament team while married, which was exceptional, due to his condition of... well, he was already co-king with Henry II.
Marriage wasn't always the union of two loving people as we know it today(well not really given the divorce rates nowadays) but a tool in political machinations. The king and the queen didnt share a room and weren't always cuddling, laughing and watching the jester do standup while in bed.
I didn't say any of that. But now that you bring that on, there's something the devs should consider:
heiresses as rewards.
In England, the orphan heiresses or rich widows were kept by the King, who administrated their lands and used them as reward to their best collaborators, vassals or "friends", in the Feudal meaning of the word (that is: loyal, true servants of their lord). Henry II rewarded William Marshal with Isabelle de Claire, one of the richest ladies in England, who gave the Marshal a quarter of Ireland, the Earldom of Pembroke, lands in Normandy, England, the Welsh March... this way William became one of the most powerful men under the Crown of England.
This "royal tutory" of heiresses gave them the power to set a complex web of alliances, fielties and loyalties that went far away from the typical feudal relationship of lord>vassal.