Now, to the question:
We are having a disagreement on the use of comprised and comprised of. My position is that comprised means composed of so saying comprised of is like saying "composed of of". What do you think?This is one of those usage questions that even linguists seem to fret over — where we don't bat an eye at split infinitives and many proudly use literally in its recent, non-literal sense. In fact, I not long ago participated in an editorial decision where one of the best editors in the field of linguistics raised this very point about a paper written by another very senior colleague. The web is pretty well papered over with discussions of this point, like this one, so nothing here is close to original.
Here's what Merriam-Webster's Collegiate (11th ed.) says, starting with their third definition:
3 : COMPOSE, CONSTITUTEThis gets it exactly right, from what I know, except that I have no idea about specifically literary usage. As is often the case, it's easy to avoid the problem, as they suggest. (There's a growing body of work in Second Language Acquisition about avoidance as a strategy among learners, by the way.)
usage Although it has been in use since the late 18th century, sense 3 is still attacked as wrong. Why it has been singled out is not clear, but until comparatively recent times it was found chiefly in scientific or technical writing rather than belles lettres. Our current evidence shows a slight shift in usage: sense 3 is somewhat more frequent in recent literary use than the earlier senses. You should be aware, however, that if you use sense 3 you may be subject to criticism for doing so, and you may want to choose a safer synonym such as compose or make up.
I'd also note that we do see some instances of 'preposition doubling' (see here), including an example pretty close to composed of of:
This league consists of mostly of players …