Yes, we saw last year when Miami had a healthy and talented offensive line they were able to run the ball with dominance and give Ryan Tannehill time to make big plays down the field. Nobody is arguing that the offensive line isn't important it would be silly not to. But, Miami already has 3 first round picks on their offensive line and to keep investing high draft picks in this area will not fix the elephant in the room which is the Dolphins defense at this time is not very good.
The Dolphins on defense have gaps to fill on every level. They are short a starting linebacker currently, they really don't have a starting caliber nickel cornerback on the roster, and the depth at defensive tackle and defensive end just isn't there. During the three days of the NFL draft the Dolphins could throw a dart at their draft board and in the first three rounds any player they take on defense will either start or play significant minutes this upcoming season.
To me in Round 1 at pick # 22 it comes down to basic math. This draft is very heavy on defensive backs and pass rushers. So to me that means Miami should look to add a linebacker in round 1 as you can most likely get a quality linemen or corner in the next two rounds. While I won't release my official mock draft until the week of the NFL Draft (I only do one mock draft a year folks) the names that will most likely be there at 22 are Zach Cunningham, Jarrad Davis, and Haason Reddick. Honestly I would be ok with any of the three (I do have one favorite which you will probably hear about in a couple weeks with the mock) as I think any of those three would step in and start day one for Miami.
In Round 2 at pick #54 Miami would be looking at either cornerback or defensive linemen. It's hard enough to predict round 1 people so to predict who will be there at pick #54 is difficult. Miami will probably take the best player on the board at either position and then take the final position in Round 3 at pick # 97. Remember this as well, many of the so called "Draft Experts" are saying this year around 50 players have first round grades on them. That's right, 50! Meaning at pick # 54 in Round 2 Miami most likely will be getting a player who would be drafted in Round 1 most years.
Miami can probably find a quality offensive guard with one of their three picks in Round 5, hell if they want to double down and take two in that round since they have three picks in Round 5 have at it. But the early round picks this year need to be used to rebuild this defense and I wouldn't mess around with that.