Gibbs is the line coach in Seattle and probably the most influential assistant in the NFC West as far as shaping draft priorities in 2010. That is partly because Gibbs is a high-profile coach. It's also because he demands a specific type of player for his scheme.
I've gone through every offensive lineman Gibbs' teams have drafted (download sortable list here). Patterns have emerged. I filtered out the years he spent in the league prior to 1995, his first with Denver, when analyzing player weights across specific positions. The thought was that player weights from the 1980s and even early 1990s might be outdated. Also, Gibbs might have been less influential early in his career, particularly when with the Raiders.
Since 1995, the players listed as guards averaged 289 pounds. Gibbs' teams drafted them in the second, third, fourth, sixth and seventh rounds. The players listed as centers averaged 302 pounds. Gibbs' teams drafted them in the third, fifth and seventh rounds. The players listed as tackles averaged 313 pounds. Gibbs' teams drafted them in the first, fourth, fifth and seventh rounds.
The Facebook discussion brought to light a Florida State-related blog entry summarizing comments Gibbs made during a coaching video (extra credit for anyone who can find the video). The summary suggested Gibbs was most particular about centers, then guards, then tackles.
An inexperienced or less intelligent player would have a harder time starting right away at one of the interior positions. Look up scouting reports for Gibbs' interior linemen and they'll mention smarts and a lack of size. "Very, very smart and plays smart," the late Joel Buchsbaum wrote about eventual Broncos draft choice Lennie Friedman in his 1999 report for Pro Football Weekly. "Average size, speed and physical tools."
Broncos guard Ben Hamilton, one of the free agents Seattle has considered this offseason, fits the description. Buchsbaum summed up Hamilton this way in his 2001 preview: "Very smart and dedicated. ... Might be able to play guard or center for a team like the Broncos. ... Lacks great natural size and ability. Is a pumped-up 250-pounder."
Sims is much bigger and more powerful, which doesn't matter in a Gibbs blocking scheme.
Since Gibbs entered the NFL in 1984, his teams have drafted one offensive lineman among the top 20 overall choices -- 338-pound tackle George Foster, selected 20th in 2003 despite not really fitting the Gibbs mold. Gibbs' teams have held a dozen choices higher than 20th during that time. His teams have held 43 choices among the top 59 overall picks, using three of them for offensive linemen (all tackles).
Gibbs' teams have held 11 picks between the 60th and 77th slots. They used five of them for offensive linemen, all guards or centers, including Dan Neil and Will Shields. Seattle holds the 60th pick this year. Three of them were 6-foot-3, one was 6-2 and one was 6-4. That's another thing about the linemen on Gibbs' wish lists. The guards and centers aren't very tall.
It's a little tougher to project what kind of tackle Seattle might select. The Seahawks' need at the position could be great enough to justify taking the most talented player, with less regard for the things Gibbs demands from his interior offensive linemen. That might be a justification for projecting Trent Williams to Seattle at No. 6, as some have done lately.