Obviously I'm not an NFL GM. Just a fan posting on a fan forum about a subject that's been beaten more than the Phins have the last 10 years. That being said:
Hartline must be re-signed. He is a legitimate #2 WR or at the very least he has the real potential to be next season. Yes, he didn't score but the blame should be shared with the dismal supporting cast. He showed he could be a deep threat and a great possession WR. He has great chemistry with Tanne, is (26) young, and is a Dolphins draftee. Not to mention he is durable. He has played in all but 4 games in his 4 years with the Phins. As the 49ers and Ravens showed, you need to accumulate talent. Not part with it. He flourished with Tanne in the West Coast offensive and will only get better, especially when more weapons for opposing defenses to focus on are added.
I like Jennings, and early on I preferred him over Wallace. However, he has become injury-prone. You can't expect that to suddenly change if he changes uniforms as we have learned with the likes of former injury-prone signees such as Justin Smiley and Jake Grove. For the NFL, 30 years old is OLD. Jennings' arrow is pointing DOWN. Phins need to accumulate players on the rise. Wallace is that player. He may be limited in the routes he runs but with further coaching that can hopefully change. His speed and star quality is something the Dolphins lack and are starving for. He will come at a lofty price tag and there is concern surrounding his character. However, if the Dolphins perform a solid evaluation process and offer a big but somewhat self-protecting contract I believe he is worth it. A lot of NFL players lose their desire for the game after a big pay day, but I'm hoping (26) Wallace's desire, pride, and yes, ego, keep him hungry for winning. Dolphins are on the rise and along with Tanne, Wallace can be the face of this franchise for years to come.
Other than speed, the Dolphins are hugely lacking in a big and aggressive WR. Someone Boldin-esque. This has to be Ireland's job to find in the draft with a relatively later pick. Someone who can bully opposing CBs. He doesnt have to be the star Boldin is, at least not immediately, but he must be able to come up big when he is called upon and at least provide Tanne with an escape clause against aggressive defenses on occasion.
Just my 2 pennies