I'm an outside observer (from canada) so take my opinion for whatever it's worth to you.
I think the ticket with the best chance to win if Biden has to be the nominee is Biden/Cuomo.
that's suicide because it doesn't meet the identity politics standard.
A Biden/Cuomo ticket would read "two old white men--no women and people of color again" ticket. And for what it's worth..if Cuomo jumps in, he'll get exposed quickly. Dude is corrupt at they come as a Governor.
He has already verbally committed to a female...so he has to stick to that. Now the question is...is she a woman of color and where is she from, and what's her background.
Biden really locked himself into only a few choices because there's not many to go around.