I'm no football coach, but if you take a chance on OL, best case scenario is you have to redshirt the kid. He MAY start one year down the road, or he may just provide depth all of his career. It's hard to say. BUT, you could instead focus your efforts on a recruit you know has higher potential to contribute. And then with future scholarships, you could pick up a grad transfer, which is essentially the same thing as waiting 2-3 years for the initial redshirted OL to potentially contribute, except you're getting a bonafide proven commodity on the transfer market later on when you can afford the scholarships.
I get it, the lines are essential, BUT this is a calculated risk either way, it's not as cut and dry as it's being made out. There are options down the line.