Youngkin is way taller than DeSantis. Not gonna work.
Biden was taller than Obama though.
Actually not. Biden is about 6'0 and Obama is approximately 6'1.5.
I believe there were just two instances in which the vice president was taller in recent decades: HW Bush was taller than Reagan (6'2 and 6'1, respectively) and Lyndon Johnson was taller than Jack Kennedy (6'3.5 and 6'1, respectively).
As for Youngkin and DeSantis, I don't think it really matters. However, I see Youngkin more as a cabinet secretary. Tim Scott would be an ideal running mate for DeSantis. Especially because of his senate experience and because he's African American. He might at least win over a few black men in a general election.