Maybe I should have said completed their OL in one year in the draft, after building it solidly over 2 or 3 yrs in a row. Examples might be:
Packers: Three starters in left guard Josh Sitton, right guard T.J. Lang and left tackle David Bakhtiari were all drafted in the fourth round. Center Corey Linsley was a fifth-round pick.
Dallas Cowboys: have had tremendous success over the past few years with building a dominant offensive line. In four years they invested first-round picks in Tyron Smith, Travis Frederick and Zack Martin, and hit it out of the park with all three. Last year, it was center Travis Frederick, who went 31st overall and was universally the most panned pick of the entire draft.
If you look at the dominate teams in some previous decades, their domination was built around an OL built through the draft: Raiders of 60's, Steelers of late 70-80's, Cowboys of 90's. How much of that is luck in drafting, intelligence in drafting, and persistence in addressing the OL in each draft has to examined. But, IMO, the only way to have a dominant OL is to wisely and consistently pursue such a thing year after year in the draft. Adding a great FA to complete the process is nice, but it is the draft where it should start and end.