Can any of the 3 (?) top OL be a plug and play starter from day 1? From what I've been reading Skoronski is that guy. I don't know about the others.
I think that is a moving target to hit, so let me tell you what I think would be a day 1 starter. Here is my list (apologize for being verbose) of what I think this team should be satisfied with, and some of the benchmarks are surprisingly easy to hit.
1) Have a comparable floor and a higher ceiling than their veteran competition. This should be the easiest to hit because the veteran competition that is on this team right now is genuinely garbage. It should not be hard for any of the top prospects to be better as rookies than what Fields had to deal with last year.
2) Have the athletic traits to compete as rookies. For this criteria, a rookie on this team needs certain athletic traits that have been talked about ad nauseum on this thread already, and we really need not dig deep there. There are at least five prospects in this draft that hit target 1 that also seem to be competitive for target 2: Skoronski, Paris Johnson, Broderick Jones, Anton Harrison, and Darnell Wright. When a rookie is competing well to hit this target, you put up with the rookie mistakes.
3) Has the work ethic to show improvement. We will see this both in how he approaches practice. During the season he will make strides in spurts, and in the offseason we should see him dedicating to improving, instead of partying. I dont know of any off field concerns for any of these candidates. So I would be happy with those five listed in (2). My favorite is Broderick Jones, but I understand why he is considered third-best.