The Dolphins started the draft with 9 picks, wound up with 10 during the draft, and left with 9 new players. So, hey, it was a success.
As far as needs, they needed some additional talent at WR, DB, and d-line. They addressed receiver and db, and JT is still available. So, I'd say they at least hit on their needs.
How good will any of these players be? Who knows. History tells us that about 60% of draft pickss have success with the team that drafted them. That would equate to 5 - likely - players who will make it with the Fish.
Time will tell who they are.