Having looked at draft success rates in the past I gotta believe that is one of the best - if not
the best - success rates in the NFL, especially when you consider what round those picks were made.
The Rams seem to have a two-pronged strategy:
First, trade premium draft picks for known talent rather than taking a chance on rookies (especially effective when you're drafting between the mid twenties and #32).
Second, identify their own potential FAs a year or two ahead of time, draft potential replacements, and coach them up - often in a redshirt year. Then, if the replacement is deemed ready let the FA walk, pocket the comp pick, and restock the pipelines.
That second thing only works if you draft guys who develop into starters, or at least capable rotational pieces. Teams who try to copy the Rams formula will collapse like a house of cards if they don't have the draft successes the Rams have year after year, Tutu's of the world notwithstanding.
AlbaNY_Ram