Look, everybody knows that Tannehill made a position change from WR to QB and actually only started a year and a half at the college level. He isn't NFL ready by any stretch of the imagination, and the injury isn't helping.
Cousins isn't ready either and if you are an AZ Sun Devil fan like myself you know beyond any shadow of a doubt that Brock Osweiler won't be starting in the NFL for at least four years.
Weeden is the only NFL ready QB left available in this draft. Weeden stats and body of work are just as good as the top two guys, he is just old.
Charles Clay is a fullback who is a good receiver. He goes about 6'2" or so and runs around 4.7. He isn't a redzone threat or a deep threat. Fleener is 6'6" and runs a 4.4 and he is a redzone threat and a legitimate deep threat.
These are two very different players playing different roles and positions.
Like I wrote in the original post, Philbin himself has said that his offense is enhanced by a prolific receiving threat at the TE position.