Can't find Rickie's age anywhere, but Angeli is 21, and guessing since Collins is a RS-SO he's 20 or 21.
We can dive into his game logs, but most of it is mop up duty rather than "poise in big spots". He was solid yet unspectacular when Leonard got hurt against PSU. His only other actual game time was the bowl game against Oregon State, which I wouldn't use as proof of anything.
I just find it hard to say definitively he's better than Collins, or that he's a better leader than Collins without specific proof.