I think the funniest dynamic for arranged-marriage royalty would be a queen who came here 100% prepared to murder her future husband and rule as a widow queen in her own right, only to discover that the king is autistic as hell and responds to her wish to rule with "oh thank god please do, I don't want to be bothered by these people. I can just tell them to go bother you instead, if you really want that. I've got beetles I wanted to study."
"I'm really not good at it," the king admits with horrible, aching grief. The country is in disarray. Peasants go hungry. Nobles trade power amongst themselves with impunity.
So the queen takes over and ruthlessly sets things to rights. Fires several generals, hangs nobles, redirects wealth to the peasantry. It isn't long before the first assassination attempt, which she expected.
She did not expect her docile, beetle-obsessed husband to go absolutely feral and fling himself at the assassins wielding a pair of sharp knives.