The Lion Guard in Frage is not the one from the tv series.
That tv series doesn't apply in any way.
This history is my vision and head canon. 

Mufasa's parents, Jasiri and Shani, had an arranged marriage as usual. They weren't as lucky as some, as they never fell in love. Only some infatuation was noticeable, but because they were otherwise very close with each other as friends, the marriage did not feel too forced oder impossible. They could have broken the tradition and abolished that law, but were not radical enough to make such a shocking change.

Nonetheless they loved both their sons with...

The kingdom of Pride Lands is reeling from the scandalous fact that the king's brother attempted to murder him and their prince with the help of hyenas, and has now been exiled under bane of death. Only one positive thing has happened; the hyenas have also been exiled under bane of death so they won't be bothering Pride Lands as much anymore. Security in the land has increased to extreme, visitors are still welcome but interrogated and watched closely, and protection of the royal family and especially of young prince Simba is now the focus of the king's Guard. Can a kingdom recover from something...