It's interesting to see that the article was written in June of 1940. A time where the Vic was still standard for the RAF. Almost the beginings of a realization that the finger 4 was the better tactic. Though it doesn't mention it directly, you can see references to what would later be called "energy states".
Good article in that it shows the expansion of ideas from all yank and bank to the possibility of a slashing attack being the best call.