currently the chances are
AB's ~40%
England ~23%
Wales ~20%
Ireland ~8%
SA ~6%
Aussie 2%
I would say SA are more of a threat than that, likely to make a semi or even the final, Aussie were unlucky against Wales and you would have to say they are better than 2%
Comparatively I don't see Wales as a 20% chance for sure but still a good threat.