It's one of the oldest debates in sport. I expect there's cave paintings in some remote part of Queensland depicting the conflict.

The mungoes and the toffs going at it, insisting their respective kind of rugby is far superior to the other.

The mungoes hanging out of their rusty utes, guzzling tinnies and, between burps and farts, screeching insults about the wobbly fatties who play union, while from the safety of their ludicrously expensive ivory towers, the toffs ignorantly and arrogantly dismissing the 13 man game as a one dimensional bore and giggling into their gin and tonics about league scrums.

About the only thing they can agree on is the ball is kicked too much in Aussie rules. Oh, and that Russell Crowe really is a New Zealander.

Debating the merits and shortcomings of each rugby code is a task too big, too cumbersome in this forum where we are also occasionally visited by heavily medicated people foolishly interested in other sports.

But in a week when the teams for both rugbys will engage in meaningful international competition, it might be timely to lance the boil that is the discussion about which players would be capable of playing both codes at the very top level.

First, however, let's review the story so far.

In the beginning, around the time women got an extra rib, a wise person decided you could have more fun using both your hands and feet, rather than feet alone. Later, this unarguable truth led to the practice of using one's fingers rather than toes to prepare dinner and the widespread popularity of rugby over soccer in three Brisbane suburbs, a small English hamlet and a pretty coastal French town.

The ruling class took over rugby, mainly because it was a little like self-flagellation and they found it helped reduce the necessity for them to cross-dress for sex. (There are studies). The working class, sick of having to play in the forwards and calling their teammates "governor", formed a breakaway group with the intention of playing a game that ensured they wouldn't have to put their head too close to anyone else's bum for any great length of time.

And so, rugby union and rugby league went their own separate ways. Occasionally a player who had pissed his inheritance up against a wall or raided the trust fund to pay for the Vegas trip would leave union for league where bread and dripping was available to the winning team, but otherwise there was not much intermingling.

The people with handlebar moustaches running union kept adding rules to make the game as complicated and unattractive as possible (thus ensuring knobody without money would bother playing or watching), while the leaguies, in an effort to spread their gospel, dumbed down the 13 man code to the point they were considering inviting other species to play.

Then, the unthinkable happened. All class barriers came crashing down. There was peace in the world, and poverty and suffering were eliminated overnight. Justin Bieber was silenced and Hollywood vowed not to make another Sex and the City movie.

It was a short lived revolution -- some of you might not even remember it -- but it lasted long enough for some of the leaguies to head back and try union.

So now you're up to date.

As a youngster I played both league and union and once had an odd dream about wearing a dress. Well, I think it was a dream, but I digress.

The point is, anyone with a keen interest in both codes will recognise that the elite athlete in one would usually make it in the other. Obviously, there are a few fundamental differences: league doesn't have many players suited to playing in a union front row while many of the angry cinder block shaped fellas who prop up the union scrum would have trouble keeping up with leaguies as soon as they ran out of the dressing room.

The generalisation that league specimens are more uniform in build, bulk and athleticism is probably right, as is the concept that union is a game suited for different shapes and sizes, although increasingly there is an imperative in modern rugby union for some of the traditional fatties to meet elite aerobic levels.

For years, of course, before union became an openly professional sport, it was pretty much one way traffic as a few of the best players went over to the dark side and tried league. Ray Price, the whirlwind backrow forward and occasional on-field lunatic from Parramatta is a classic success story. Price is suitably a league legend and was on his way to becoming one in union before he decided his family needed to eat.

The traffic didn't start heading both ways until the mid 90s, but thinking back over the decades there are a bunch of leaguies I would have loved to have watched play union: from the 60-70s, players from the great Souths, Saints and Manly sides and in the mid to late 80s, just about anybody in those all conquering Kangaroos sides would have been brilliant in union. Similarly, the mid 80s produced a startling bunch of Wallabies who would have creamed it in league.

Union's Mark Ella was about the best player I ever saw up close. I have no doubt he would have been a sensation in league. (How insane is it he retired at 25?) League's Wally Lewis was of the same quality. They were both on the Australian schoolboys rugby union squad in 1977.

Other big names who opted against crossing over include David Campese. There were understandable doubts Campo could cut it in league because of his defence, but that presumed he couldn't tackle. He could, he just didn't seem to like it much (hello, Quade Cooper!) Regardless, he was an attacking gem, arguably unequalled in both codes.

The list for both sides is enormous, so in the interests of keeping this drivel to under 80,000 words, let's quickly examine a few recent ‘iconic' teams and speculate which players might have been able to excel in both codes, before looking at the current Kangaroo and Wallaby squads.

In 2007 the Australian rugby league named its team of the century. I'm old, but not that bloody old so I didn't get to see every player named in action. But it's hard to imagine any of them would have struggled too much in union.

For my money, Lewis (where to play him? Hmm, inside centre), Mal Meninga (a No 8 or outside centre), Andrew Johns (at 10), Ron Coote (classic backrower), Johnny Raper (as a pivot in the Stephen Larkham mould), and Bob Fulton (who actually played union as a 5/8 for the Australian Defence Forces side) would have been standout Wallabies and Artie Beetson would have been devastating in the right era.

One of the most successful eras for Australian rugby union was the 10-year period from the birth of professionalism in 1995 to 2005 when the ARU named its "team of the decade".

From that lineup, I expect captain John Eales -- despite being the consummate union second rower, and potentially an awkward fit for league -- would have succeeded had he jumped ship. He was simply a great athlete and incredibly intelligent to boot. George Smith, the great backrower is a no-brainer. He would have been a great leaguie along with Toutai Kefu (as a league prop).

The entire backline would have made a mark in league: George Gregan, Stephen Larkham, Tim Horan, Jason Little (think Steve Rogers), (a fit) Ben Tune (bracketed with Campo), Joe Roff and Matthew Burke. I'm quite positive Horan, Roff and Burke would have been sensations.

Interestingly Lote Tuqiri, the league-union-league international was named on the bench as part of that squad.

Some union types are disparaging in the extreme about the league players who have come across in recent years, but I'd suggest they've generally been of great quality. It's just a pity guys such as Wendell Sailor, Timana Tahu, Matt Rogers and Tuqiri didn't get a chance to play under the current rule interpretations which encourage attacking, ball-in-hand play.

Two of the more promising players on the international union stage at the moment are former leaguies, New Zealander Sonny Bill Williams and England's Chris Ashton. Certainly one of the best players England has ever produced is dual international Jason Robinson while veteran All Black Brad Thorn has been top shelf for both codes

So, to the current Australian squads. Who amongst the leaguies would be great union players and are there Wallabies who would be lining up against the talented Kiwis in the Four Nations final this weekend had they ‘crossed over'?

For mine, Darren Lockyer, Billy Slater, Cameron Smith, Jarryd Hayne and Todd Carney would be guns in Wallaby gold while Petero Civoniceva, despite coming to the end of his career, would be a good choice No. 8 in the Cliff Palu (former leaguie) mould.

A bunch of the current Wallabies squad actually have some league experience, although it was before they matured into elite players. A free running Rocky Elsom, nowadays, would be a hard man to stop in league.

Kurtley Beale and Quade Cooper will likely opt to test themselves in league after next year's union World Cup. Finally in shape, Beale is showing his unbelievable talent, while Cooper is potentially the next Benji Marshall.

Matt Giteau, son of league toughy Ron, is going through a rough patch at the moment, but he would relish the extra attacking opportunities in the 13 man game while James O'Connor has shown enough to suggest he has the goods in any company.

My bolter would be David Pocock. He has a very specific role as a union fetcher that doesn't translate to league, but the fella is astonishingly strong, catches and passes with aplomb and is a devastating defender. Remember Terry Randell?

Next week, a really short yarn -- the AFL players who would make it playing rugby. Just kidding!