Mike Sainristil probably is a better fit in Round 2, compared to Pick # 29, because of his well below average size. Yet, with Sainristil checking the vast majority of the other boxes, it wouldn't surprise me if the Lions drafted him with Pick # 29, He has tremendous ball skills and intangibles. Mike Sainristil has come a very long way as a CB, as he was a WR wih Michigan before his final 2 seasons.
If the Lions trade down from Pick # 29 and draft Mike Sainristil, that will likely be a good draft outcome. I don't expect him to be available with Pick # 61.