If they want to go "all in" this year then yes, they have to be active in free agency, and early in free agency. The positions of need are as you listed. DL, LB, OL, RB, WR., in that order with DL and LB being just about equal.
I think they can address OL, WR and RB in he draft. I think LB is a 50-50 split draft and Free agency. On the DL, I do not think they will find any quick fixes in the draft unless they are extremely lucky. I think they need to go big in free agency. Even if they sign 1 impact player on the DL it will greatly improve their run defense, assuming the find some real LBs.
Will Jerry just this once change his philosophy and sign someone like Christian Wilkins of Justin Madubuike? I have a feeling Chris Jones, Wilkins and Madubuike might be give the franchise tag by their teams. If that's the case then I would go hard at Patrick Queen. Baltimore is already paying Roquan Smith $20 million/year. I doubt they will give Queen a similar contract. If the Ravens let anyone go I think it will be Queen. The problem is there are a few teams that will go hard at him including the Eagles and Commanders. The Commanders have a ton more money than Dallas has.