An epidemic of prepositional anarchy?

In his linguistically thought-provoking Guardian article under the heading "Back to prep school", Andy Bodle reckons that Harry Blamires, the author of The Penguin Guide to Plain English, is far from alone in thinking we are in “an epidemic of prepositional anarchy”.

His bottom-line advice is to "check the dictionary", although interestingly (and perhaps contradictorily?), he also refers to Google Ngram Viewer as a tool for trying to determine which version can be regarded as 'more correct', in cases where several 'legitimate' options exist, e.g. bored with/of, obsessed with/by, identical with/to.

Further reading: comprehensive Wikipedia page on prepositions, postpositions, circumpositions and adpositions.