Literally every scouting report had the following to say about Tannehill coming out of college:
Strong arm, accurate on the run, throws the ball outside the hashes with zip, accurate on short and intermediate throws, all the physical tools to be an NFL QB, will lock on to primary receiver at times, intelligent, good at improvising but will make a head scratching throw or two, needs a couple of years of development before facing live bullets.
Pay attention to the last one, the scouting report is that he was raw, inexperienced, needed to sit for a year or two, needed refinement etc.
Well he started from day 1 and from year 1 to year 2 his numbers improved, except for interceptions. But interceptions go up when you're asked to throw more and since the Dolphins went away from the run a lot, that's what happened.
So, according to many so-called experts, Tannehill was supposed to sit for a year, maybe two. He wasn't ready for live bullets. He would take a few years to reach his ceiling.
As far as I am concerned, he is ahead of the curve.
If he had been a 3 or 4 year started in college and was still locking into receivers and making boneheaded throws, a la Chad Henne, I'd be concerned. He was a one year starter in college and not only did he play much better than Chad Henne ever could, he had one of the best statistical seasons at QB for the Dolphins since Dan Marino retired. I know that isn't a very high ceiling, but I consider this combined with his relative lack of experience as cause for hope.
On top of all that, has he ever had a coach develop him as a QB? Let's see what Lazor can do with the kid. This will be his first time with a true QB mentor.
I agree, as far as Tannehill's development is concerned, he's checking all of the boxes. His rookie season was a typical rookie season. He had the ups and downs you'd expect from a kid that was thrown into the fire like he was. His second season he improved in almost every statistical category possible despite being protected by the worst offensive line in the NFL. Again, about what you'd expect a young quarterback to do when put in that situation. Nothing I've seen from Tannehill so far has me worried that he's not on track. I fully expect to see him increase his completion percentage again, throw more touchdowns again, and throw fewer interceptions in the process.
If the Dolphins give the kid better protection (doesn't have to be excellent, just mediocre), give him a consistent rushing attack (doesn't have to be excellent, just decent) to feed off of, and he works well with Lazor's new ideas, then I think this team is well on its way to a ten or maybe even eleven win season. I feel the acquisitions of Albert, Smith, and Moreno have us well on our way to accomplishing those things.