Frederick's focus is on the controversial point of 'collective intentionality,' as it were, as it pertains (or for Frederick, fails to pertains) to things like institutions. It reminded me of Grice!
One passage by Searle cited by Frederick mentions 'cooperation', which brought me back to Grice! In his 1965 Oxford lectures on implicature, Grice distinguishes between cooperation and helpfulness. In fact, he prefers helpfulness -- this may relate to Searle's example of 'going on a walk with another person'. Only that one has not to be too cooperative for that! (Only keeping your co-walker's pace! It's VERY RUDE otherwise!).
In those lectures, Grice speaks of a sort of equilibrium between principles of self-interest and benevolence, which may apply to Frederick's discussion.
The examples provided by Frederick are genial -- take Graeco-Roman slavery, for example. Surely a slave does not want to be a slave. A Greek slave holder may well become a slave back in Rome. How does the Graeco-Roman institution of 'slavery', if institution it was, can be accounted for in terms of collective acceptance and collective authority? Surely Frederick is right that Searle is being a tad _too_ Griceian!
Frederick also touches on the important point of collective intentionality versus the aggregation of individual intentionalities. Take Grice's cooperative (or cooperation, as I prefer) principle -- a joke on Kant's categorical imperative. It is formulated in the second person imperative: "Thou shalt not...". It is NOT formulated, to emphasise a point by Frederick in another context, in terms of "We": "We should cooperate". Does the grammatical distinction matter? Perhaps not.
It is useful to see cooperation as involving the idea of a non-zero-sum game. Let G be the goal of Abe (to use Frederick's example) and G' be the goal of Betsy (again to use Frederick's example). Some concept of joint or collective intentionality, when Abe and Betsy can use "we" ("We shall walk together") may be the result of this idea that the intersection between G and G' is not vacuous. I.e. there's something that A and B share: some, why not, desired-dependent intention on A's and B's part -- to take a walk together.
It's different when it comes to the poor Greek oligarch that once the country becomes a Roman republic, he becomes a mere 'paidagogos' (Roman slang for 'slave') in Rome. And so on!