True, Royal Marriages were fixed but not all of them were disasters. Many times the king/queen were brought together at a young age, and grew up together as they were both prepped to rule the country. Many times they grew to love each other. The Europeans just didn’t throw people together and tell them “ok, go make an heir.” That’s just anti-Catholic lies about the “dark ages” of history.
If both were good Catholics, as happened a lot, then I’m sure their marriage was enjoyable. (God knows from all eternity who will be married, so even in the event that it is “fixed” beyond your control, good can come from bad or there might not be any bad at all.). Even Henry VIII and Catherine’s marriage was good for a while, until he couldn’t have a son and went off the deep end.