I really don't think there is much difference between elite players @ any position, those who are, get drafted higher & paid more. My point is you can develop OL just as you can develop a WR so taking BPA approach to the draft you take the highest rated player in most glaring area of need. Jason Smith, Baylor was drafted #2 overall to be their franchise LT in 09 (you don't spend high picks on RT). OT Rodger Saffold was taken very next year #1 overall in the 2nd rd. both to set the ends for Sam Bardford who was the #1 overall pick in the 2010 draft.
So you are suggesting that the St. Louis Rams select another OT with the 2nd overall pick in the 2012 draft, because this is their most pressing need once again? Hypothetical but we probably wouldn't even be having this conversation, if Rams had a stud WR like Hakeem Nicks or Dez Bryant, but they don't unless they select Blackmon sitting right there for the taking. Studiying the draft as I do, there isn't the same drop off from Kalil to Ohio State LT Mike Adams as there is from Blackmon to Dwight Jones. So if they still require more OL help they can more easily address this later in 2nd & 3rd top of each round. Take it from me the talent evaluation of WR group, as per Texans need, gets much tougher to project after the top 3 or 4 guys come off the board while the OL continues to crank out almost certain starting material into the 3rd & 4th rounds.