I think they complement each other quite well.

[ though he hardly minds having aron with him for company, it's relieving to know that he can leave her at home with kain as company. though he may have "interrupted" their moment, there's affection in this one, too. ]

You'd be surprised. She's young, so her bids for attention from the others sometimes go unaddressed - Kain has been an excellent friend to her in that sense.

[ he gets scratches behind the ears for that. who's a good boy? you are, son. ]