We can draft a WR. This is a rebuild.
The dropoff from Onwenu to Sow is not much, and not worth the FA dollars which can be spent to fill a real hole like FS or tall press corner. Same applies to Duggar, save the FA dollars for a greater need as we have Mapu behind Duggar with not much of a dropoff.
The drop-off isn't known yet, since Sow was a rookie and played at two different positions.
What is known is that Onwenu is probably one of the top FA OL out there. You NEED to sign your own guys who perform above expectations, and you can't have too many good OL. With Andrews, Sow, Mafi, Cole Strange, and a draft pick (presumably), the Patriots will have FIVE of their top seven OL on rookies contracts, and their starting center, if he returns, is only hitting the cap for around 7million.
This team can and must invest a lot more in their OL going forward, and a good start would be to re-sign Michael Onwenu! Familiarity on the OL is critical to success and this group should begin to gel beautifully together going forward. DO NOT let Michael Onwenu leave.
I'd try like hell to keep Dugger, Jennings, Wilson Sr., Henry, and Bourne, as well. I want others back, too, like Austin and Reagor. They have the money, particularly if they're rebooting with a rookie QB.
Back to the topic at hand, I think QB is critical (unless you can get a FA who's more than a placeholder - Mayfield, maybe? Fields (please no, but...)? Solidifying the middle class of the team, which includes Dugger and Onwenu, helps that process tremendously.
There are a lot of solid foundation pieces in place to develop.