Well revolutions do start at base level, and I think the examples demonstrate a relatively quick process. Some of the coaches of that era were some of the great thinkers - Warren Ryan, Roy Masters, Bob Fulton. Ironic that the greatest coach still plied ahead with an old style hooker, but given the backline at his disposal the Michelin Man could have played dummy half and they wouldn't have been any worse off!
Not sure - I think we might be looking at an example of a player-driven innovation, rather than coaches. Elias & Cochrance in particular expanded the hooker's role themselves as they rose through the lower grades into first grade. I'm struggling to think of an example of a first grade coach in the mid-1980s manufacturing someone to play the new/expanded hooker role/skills that Elias, Cochrane & co. were bringing to the game.