I would roll with Tannehill in 2019, with approximately $35m-$40m in cap space they'll be able fill in the roster. The 2020 season is when I'd cut Tannehill loose and hopefully by then, Miami will have found it's QB of the future. 2019 also may be the year to start trading down, if possible, in the draft; being it's considered to be deep at positions of need for Miami.