Below is a simple graph showing the different components used to determine fWAR. I re-engineered the values, so they may not be exactly correct, but they should be close.
Items of note:
Orioles had the second worst rated defense in baseball, bested only by the Mets.
Their base running ranked 22nd overall.
Their hitting ranked 19th overall.
Simply put, the Orioles did not do anything particularly well on offense. The greater problem may be pitching, but it is not as if the Orioles can stay firm with their offense either. Getting league average performance out of their fielding would mean an improvement of 4 wins. Almost all of that could be attained by getting Mark Reynolds away from third base or last year simply being an anomaly for him. Base running make become about league average with Vladimir Guerrero and Derrek Lee gone and result in a couple wins. This still leaves the team in need of about 10-15 more wins from their offense to be considered peers of the Rays, Red Sox, and Yankees.