I’m sorry, CSD, but your basic premise is wrong.
First, the Cardinals certainly have prioritized the offensive line during Keim’s tenure with two out of six first round picks being offensive linemen, and nine out of a total of 42 draft picks being offensive linemen (the next most targeted position group are wide receivers with six). In the same period, they have signed 19 offensive linemen from outside the organization to the active roster (not counting draftees), with three of them being on huge 5-year deals. I don’t know if they have addressed another unit more, but I doubt it.
In the same timeframe the Patriots have had 49 draftpicks and have spent 10 of them on offensive linemen (nine on defensive linemen, and eight on linebackers), but only one in the first round. They have brought in 19 offensive linemen through free agency as well, but none of them have been on big contracts.
You are right, though, that they have an effective offensive line, and I think it has almost everything to do with their offensive line coach, Dante Scarnecchia. My theory is that most of their success (if not all of it) are due to continuity in the coaching staff and the front office, and Scarnecchia has been with them forever. He knows exactly what he needs to make their offensive line effective, in part because he knows what Tom Brady needs in an offensive line. Of the five starters right now, four of them they have drafted themselves, while two of their four backups have joined them from other teams. Of the nine players, I am willing to bet that none of them would get what is considered a big contract on the open market, but they fit exactly into the Patriots’ offensive line because of Scarnecchia, and thus, according to my theory, you can’t just copy what they do because it is the result of many, many years of coaching and knowledge.