I'm also going to say something widely unpopular that will ultimately show my age.
I don't think we should look to teams of old (anything prior to 2003) for insight on how we should field a team today. If we had fit, 25-year old Horans, Greys, Larkhams, Campeses, Lynaghs, Flatleys, Kafers, Eales or Kefus available for selection for todays Wallabies team, I would select a whopping none of them.
I'm 23 and people often refer to these players as the golden age of Australian rugby. I've dug up old tapes, I've trawled YouTube and I've done everything I can to try and educate myself and I've ultimately found the games, skills and defence of these eras absolutely wanting.
Watching the Roar's Wallabies backline highlights from 1991 to 1998, and 1999 to 2001 there is absolutely no structure or commitment in defence. Every part of play is devoid of what we now consider basic skills.
It (largely) looks like a bunch of 35 year olds playing semi-contact Subbies third grade after a huge night on the piss at their 17-year high school reunion, with the hangover being compounded by a week of not sleeping due to their newborn baby being a nuisance and the general playing ability being made all the worse as they haven't held a sports ball, gone for a jog or had anything to do with Rugby (as it is today) for about 13 years.
Of course, this is to be expected with the game only becoming professional in 1995. I will concede it does get significantly better circa 1999/2000, but even then it doesn't hold a candle to today. If 2016s shoddy Wallabies side played 1999s RWC winning Wallabies side today it'd be an absolute shellacking.
Where am I going with this?
Oh yes. This also all seems very obvious. Of course the came has moved on in terms of physicality - today's S&C programs have ensured that. Today's players would spend more time in a gym in a single season than the 90s players would have over their entire career. They also have access to great nutrition and supplements.
But the game has also moved on in terms of skill sets (the players pre 2003ish seem terribly uncoordinated), in terms of commitment / physicality / technique in defence (this is largely a product of professionalism - so many flailing arms pre-2003), in terms of structure (the alignment and defence in these videos is pathetic), in terms of the set piece (hardly any jumping in the lineouts in the 1991 to 1998 videos, and scrums are entirely different), in terms of tactics and patterns and in terms of the rulebook.
Rugby Union in 2016 is barely even the same sport to Rugby pre-2003. It should not be treated like it is. Because something worked pre-2003 it does not mean it will work today. In fact, I'd almost suggest that if it worked then it will definitely not work today.
Horan / Kafer / Larkham / Eales / Campese etc. were all fantastic players for their time. They were the prototypes of the players we have today, but they should not be used as the definition of how we should expect players to play today, or the roles that players with a certain number on their back should perform.
TL.DR; just because we didn't use the dual-playmaker system when Timmy Horan was floating around doesn't mean we shouldn't use it today. Timmy Horan essentially played another sport.