OTL he got married to Anne de Mowbray and ended up as duke of Norfolk. While that could still happen, it was seen as an unpopular move due to the legal shenanigans involved - which is why I'm toying with marrying her to another heir (a Howard sounds good) to the dukedom.
Likewise OTL, his brother was engaged to Anne of Brittany. Now, Anne will still be born and **spoiler alert** succeed as duchess, however, how would France react (better or worse) to Anne marrying Richard? Would it be a good idea to give him practically his own country? And if he doesn't marry Anne, who might make a good match for him?