*waves* Hi, Conner!
No, but seriously?
Francis needs someone to ground him - it’s not that he’s flightly or anything (though he does get easily bored), it’s just that he is a) a member of the aristocracy so really, has no idea what the ‘real world’ is like, spending most of his time behind the gates of fancy houses, b) is the youngest of 4, by a fair few years, so is rather sheltered as a result of this, as he had everyone looking out for him, and c) has spent his pubescent years having to pretend to be a girl, so is rather naive and suffering under the sheltering society gives to female children. Which his mother and brothers are attempting to counter, but there’s only so much they can do, being not a man and at the front lines respectively. So he has pretty much no real-world experience, and so needs someone to anchor him as and when he learns.
He also needs someone fairly easy-going, as Francis can get worked up about things - mainly things he’s learning, or things people have done that annoy him (he has the temper that comes with his hair colour) but is also someone capable of at least keeping up with him, even if they don’t fully understand his rants on magical properties of dahlias, for example.
And, probably most importantly, he needs someone that understands that he will probably end up having to pretend to be female for a good long while, until the war ends at least, and be able to deal with the fallout that follows. And someone that can deal with the fact he doesn’t really mind the wearing dresses thing - except for corsets, but that’s understandable - and while he probably wouldn’t have ever worn them if it wasn’t for the masquerading himself to avoid the draft, he actually quite likes them and will sometimes wear them even if it’s a day where he can get away with wearing male clothing.