Unfortunately, the Economist Style Guide adopts some conventions that make language less precise, not more so.
For example, it discourages the use of commas in sentences that contain a series of items (a practice that introduces ambiguity into such sentences).
It exhorts
"Do not put a comma before and at the end of a sequence of items unless one of the items includes another and. Thus The doctor suggested an aspirin, half a grapefruit and a cup of broth. But he ordered scrambled eggs, whisky and soda, and a selection from the trolley."
This practice introduces ambiguity as to whether the last two items of a series are actually a grouped item (as is normally indicated by the conjunction "and") or whether they are two independent items in the series. Punctuation is meant to reduce ambiguity; this practice espoused by the Economist serves to increase ambiguity.
In short, this style guide often panders to language laziness and cultural conventions even when those conventions degrade linguistic precision. This lessens its worth as a style guide.