This is exactly the reason he may remind some people of a young Brady. The potential is there, but as of right now, he is showing flashes of brilliance, while making plays to win when the team needs them the most (clutch, late in games). vs. Atlanta, Cincinatti, Pittsburgh, New England are all games that come to mind in which he was clutch. I'm sure there are 1 or 2 more. And he still has 2 more games to play in the regular season.
Statistically, Tannehill is the 2nd best quarterback in franchise history. Granted, Griese played in a different era and was a winner, but those teams lived and died by the running game.