Seahawks have a solid to very good, and still improving 6 man group of Okung, McQuistan, Unger, Sweezy, Giacomini, and Carpenter.
However, after that it gets a bit hazy but Moffitt and Jeanpierre are talented in their own ways and both have starting experience.
I wouldn't say the Seahawks haven't added anybody to the competition they did draft 3 players... Ryan Seymour, Jared Smith, and Michael Bowie. 7th round selections but that goes without saying the potential of those players under Tom Cable: Smith could become Sweezy 2.0, Seymour has as good of a chance as anybody to win the starting RG spot, and the 21 year old Bowie with exemplary hard work and the greatest of determination could become the best lineman we have in 5 years (yes, even over guys like Okung and Unger, not saying its going to happen but the kid just dominants on the field, and he's only discovering the tip of his iceberg that is his potential. But again one has to put in the work towards greatness, its not just handed to you on a silver platter).
Then the Seahawks also added the highly regarded Alvin Bailey who many pegged as a mid-round selection plus versatile Jordan Roussos through the undrafted ranks. Not to mention holdovers Mike Person and Rishaw Johnson, two developmental players the Seahawks seem keen on.
Seahawks have their linemen, Cable said so himself, they just need to stay healthy, and build into a big, cohesive little family of necessary chemistry.
A team can have 5 guys with the best, most elite of measures at each position but if they don't know how to work together and communicate effectively, they still could be one of the worst O-lines in the League.
From what I take and understand the Seahawks care more now about being simpatico than simply acquiring elite talent.