I fingerprinted each of the 12 opinions for style. Then I ranked every opinion against every other style profile and assembled the results. A few things jumped out. A June Marshall opinion involving Exxon and a May opinion involving animal rights seem to have much in common. They have an identical ratio of short to long words, 2.72.
Animals apparently require a higher level of obfuscation than oil companies, however.
Most of the opinions seem to cluster around four reasonably distinct styles. For a sanity check, I confirmed that Marshall's opinions were probably not written by Tom Clancy, and almost certainly not written by Louis L'Amour. The very best stylistic matches I found, however, were with other sample profiles supplied with the Corporate Voice software. Every opinion I tested scored in the high 90s. Most of this should not be taken too seriously.