You can't be first tier without having won titles of some sort. Coach Frost has potential to become a first tier coach, but nowhere near that yet. If he is able to run the table this year and go 11-0 and win the conference title game to go to 12-0, then that is respectable for a second year head coach. If he loses to USF and finishes second in his division, then you can see the upward trend.
First tier are the likes of Saban (took a long time for him to become a first tier coach), Harbaugh, Urban Meyer, Dabo, and the like. National title winning level coaches at the college level or took an NFL team to a superbowl or won the division in the NFL (not an easy thing to do).