I'm sure Horowski mentioned this, as these kind of cross connections are his favourites, but I had forgotten.

He did! At least once, and maybe more than once, but I've at least run into it more than once in my Spanish Succession reading.

For a combination of the Stuart with the Churchill gene pool, he sounds, except for his death, amazingly sensible, but maybe in the end those genes got him. :)

Hahaha, that's hilarious. Yes, new headcanon, that's exactly what happened.