I would defininetivly challenge the gurus on this subject. I change my focus passing depending on oppositions formation. And find it extremly efficient.
For example counter attack down both flanks as an answer to the AI's 4-2-4, force the AI to drop the 4-2-4 almost immediately.
Neither do I agree that flank passing require width. Perhaps if you experiement with one style over many games, it will show. But vs. AI formations that do not include M R/L, your own (A)M R/L still have plenty of space and you often get either one on ones vs. the AI full backs or even two on one, if your striker helps out.
These comments are not meant for the building of a core tactic. But
IMO focus passing is a very easy tool to use during matches. You don't need to tweak a lot. You just change one thing and force the AI to adopt.