I don't think he will be sitting there for the Dolphins at #5. I'm not going to ignore the recent trend. Trading up for first round quarterbacks is the rule, not the exception. Until last year's draft, every first round quarterback outside the top 3 picks since E.J. Manuel had been acquired by trade up.
Teams don't sit around and wait for the first round quarterback to fall to them. I realize the logic that Tua is an exception, and not worth a trade up gamble, due to health. But that aspect is offset by Tua's spectacular rating prior to this season and prior to injury. Many fans who react to every new detail are throwing that prior rating away. But organizations that calmly evaluate the big picture, and especially the astronomical value of the quarterback position, are not going to throw it away.
BTW, that stat of at least one first round Super Bowl quarterback automatically goes to 44 of 54 this season because every starting quarterback remaining in the AFC playoffs was drafted in the first round.
After watching Tom Brady's decline this season I'll be particularly interested to see if New England is willing to just sit there and allow everything dynasty to slip away. Detroit is an obvious trading partner for the Patriots since Matt Patricia would know the New England roster and which players he covets, along with draft picks.
And if Patricia has any aspirations of a fraction of Belichick-type career then he'll understand the worth of grabbing Tua for the Lions, regardless of having Stafford, who most likely continues to lead them nowhere.
Detroit could also play chicken with the Dolphins front office, similar to the Vernon Carey situation with the Vikings in 2004, by imagining or exaggerating their trading partners.