Crossover between the two rugby codes is not unheard of. The victorious British Lions in South Africa in 1997had three quarters of their three quarter line made up of players who had played rugby league - Alan Tait, Scott Gibbs and John Bentley.
if you wanted to get into GAA analogies, it would be the equivalent of getting the Ulster teams (say Donegal, Monaghan, Tyrone and Cavan) to play, say Thomas Davis of Dublin. Even go one further, call it against Oliver Plunkets Eoghan Rua. Would you think the best teams from the Ulster province could beat the best club team from the Number 1 county with only 2 weeks prep?
Actually what it would be really like would be getting a railway cup team together, fly them to nz for a fortnight, and then back , and get them to play the worst of the leinster or munster intercounty teams, say wexford.