A great many ideas may be perceptive about what is wrong but not at all about solutions. It is not about being "correct"; neither "perceptive" nor "prescient" entails "correct."
I would not even think of listing what was "not perceptive" out of context. For example, as I noted, he said in a letter "I'm all for Empire." That is worked out much later in his admiration for the Roman Empire in "Virgil and the Christian World." I really do not agree that the solution to the problems of modern capitalism (many of which Sanders aptly identifies [which does not mean his solutions are "correct") would be solved by Eliot's "Christian Society" or his "Culture," let alone the Roman Empire at its least violent, even if it were possible to create: his vision is exclusionary and hierarchical.
I was not at all conflating "Notes toward the Definition of Culture" with "The Idea of a Christian Society." Believe it or not I have read both many times. I said "as in"; that does not mash anything or confuse either. In the former he spent a great deal of time and space on the relation of what he imagines to be the few "great" cultures and others he sees as "satellite cultures" as in England and Scotland or Wales. That is what I had in mind in contrast to "Empire," and I assume anyone who has read both at all recently will see the relevance.
If you do not see how calling Christianity "the only full revelation" and saying “The World is trying the experiment of attempting to form a civilized but non-Christian mentality. The experiment will fail" divides us and is now a disturbing political problem, I can't help you. (See Donald Trump and the response of Suzanne Barakat, the sister of a Muslim student killed alongside his wife and sister-in-law last year in an attack in North Carolina--just being mutually helpful.)
It would be interesting if, just once, we could have a discussion in which you did not feel the need to write as if I need correction and information from your apparently greater knowledge and understanding. It is a bit silly, not at all called for, and very tiresome.