I think that is a stretch. The technical ability within the rules of rugby, especially in the pack would be difficult. I am not saying there would not be players who would be decent enough because there are just some people who naturally excel at whatever they put their mind to, but generally I think there is a higher chance of failure, if you are really saying ANY team.
Rugby League players find it extremely difficult to come over to Union and they already have that stamina and the basics of a fast paced rugby game.
It would certainly be interesting, as I am not as confident that there is a difference in physical attributes. Added to that every single player needs to be up on all aspects of Rugby, they all touch the ball. Handling, etc. needs to be sharp for all positions. Over the weekend there was also a couple of examples of second/back row players performing top class kicks. There is a more all round technical aspect to rugby players that you may not get in most NFL players.