I was reluctant to comment but just briefly:
I coach gymnastics and have done so at a local and international level. I have had the privilege of representing Ireland as a coach at international level. I have not coached rugby at all, though I think it's the greatest sport in the world.
Gymnastics is way way WAY down the pecking order of sports which young people will take an interest in and stick with. As such I've had an untold number of disappointments with talented individuals dropping out of the sport in favour of hurling/football/soccer/athletics/rugby/dance etc etc.
Based solely on my (entirely biased) viewpoint I would prefer a young athlete to make a go of representing their country/province on a world/european stage, rather than sticking with a local club for whom they might well perform at the highest level, but of whom no-one outside of Ireland will recognise.
Once again this is entirely my own preference but I've seen serious talent lost to local GAA clubs which might have helped put Ireland on the map in various sports and it is deeply frustrating.
As a young athlete I wish Sweetnam all the best for the future, whatever code he chooses.