Why turn down an adoption or MOTH? Fair enough the marriage proposals because you might get a better offer but you don't lose out on future adoptions if you accept some do you?

Or were you just trying to be dynastically realistic? (The Romans adopted as a matter of course, Tiberius teh second emperor was adopted I think but medieval kings didn't as far as I'm aware)...

I think of it as representing the senior nobility rather than the immediate royal family.