You say fix OL and DL but a lot of the team cap is invested there already. We couldn't have a more expensive DL than McCoy, Short, Poe, Butler.
Our #1 pick went on Burns to go with Addison and we picked up Irvin as well.
On OL Paradis was a big ticket FA Turner has a high cap hit and they drafted 2 tackles.
When all is said and done it's not throwing money at the lines that matters for me it's getting good value out of the expensive pieces. Considering investment both units are hugely underproducing. I put that on GM, coaches and players.
My solution is to move the guys who are going through the motions. I would let Poe and McCoy go. I prefer McCoy to Short but we can't get out of his contract next year. Let Williams and Van Roten walk. I would trade Turner and draft a guard. Move Daley inside. Paradis will be here another year unfortunately. Then I would get a new coaching staff and end the comfortable favorites game which RR loves to play.