The rules of SEO are gradually changing. But I’ve spoken to a couple of clients in the last year who seem to be pursuing outdated policies “because that’s what our SEO company tells us”. There can only be two reasons for this: either the SEO company isn’t keeping up; or they’re charging for writing content, and keeping up with the times doesn’t get them as much work. It’s why I’ve always said that unless you have a major project and/or a serious budget, outsourced SEO can be a waste of money.
The specific ‘rule’ I’m referring to here is having many pages on your website covering slightly different wording of the same topic. I’ve certainly recommended this in the past: if you want to rank for ‘how blue widgets work’, ‘what is a blue widget?’ and ‘blue widget design’, I’d probably have said that you needed separate pages for each, with quite different content. Nowadays? You’d be better off targeting closely related terms on the same page, because Google is more interested in topics. Cover all of those terms if you can (and while you’re at it, use Google’s ‘related searches’ to find more). But if you want to do well, build up a single, more extensive resource that will be of use to more people.