Ideally you use free agency to plug your gaping holes (OL) before the draft so that you can draft the best player available. Jeff Ireland never quite learned this so he had to "part ways" with the Dolphins. The new GM should go after an OL or 10 before the draft. This team has too many holes to draft based on need only.
I've always felt that free agency should be used to fill the gaps where the draft is weak at a position of need. In other words the team has a need (hypothetically) at DE, the draft is not deep at DE so you look to free agency to fill the need and address other spots in the draft.
The draft should be where you build the foundation of the football team. We've never done it that way. As a matter of fact I'm not sure what we've been doing. Seems like we drafted for depth more than finding starters or difference makers. We drafted Odrick when we already had Starks and Langford (and Merling who sucked), traded up to get Daniel Thomas when we already had Reggie Bush in house, drafted Clay when we already had Fasano, drafted Egnew when we already had Fasano and Clay, Miller when we had Bush and Thomas...in the process we passed up some playmakers and positions we needed to fill...like taking Dion Jordan last year when we have Wake and Vernon and we needed O-line pretty bad.
Hopefully the new GM has a draft strategy that doesn't look like he's flying by the seat of his pants.