I don't think Grier really revealed anything there, obviously.
Adam Gase hates the spread and all else being equal, he'd like a guy with pro translatable experience. He also is a Mike Martz disciple through and through when it comes to valuing first and foremost how a guy operates the offense from inside the pocket.
I don't doubt they want a winner, a guy that handles the team, the room, etc. I think everyone wants that but if Grier points to that first and foremost, there's no harm in assuming he did so for a reason. But I notice he slipped in there a reference to being a winner in high school. I think there's a reason.
Josh Rosen only won 18 games in his three years at UCLA but he led one of the best high school football programs in the country. Mike White lost a lot of football games at South Florida (4-11) won a lot in 2016 (11-3) with WKU but then only went 6-7 this year. But he was 13-0 and a big time performer at University School in Fort Lauderdale. Tanner Lee didn't win in college but he won in high school as well. So Grier's standards can really be bent any which way you choose.
If I had to take the concept of being a WINNER and really focus on what it means conceptually, apply it to these quarterback prospects, a couple of guys do stand out. Clearly Baker Mayfield. Sam Darnold. Riley Ferguson. Brandon Silvers. Mason Rudolph. J.T. Barrett. Luke Falk. Lamar Jackson. Kyle Kempt. Chris Streveler. Bryan Schor. Logan Woodside. Quinton Flowers.
But it's good to keep in mind there are probably four different individuals and collectives in that room whose voices matter. There's Gase and his staff (mainly Loggains) first and foremost, Chris Grier and his staff, Mike Tannenbaum, and Dan Marino.