Done a look on Wales online if the 4 best 3rd placed teams come from grups B,C,D, F, then well will be D3 which will be Turkey or Czech Republic, I think that's the most likely scenario but nothing is certain. The only scenario I see where we come up against Northern Ireland is if the 4 best third place teams B, C, E, F and that would require Sweden beating Belgiium or Ireland beating Italy, and the Czech Republic failing to win tomorrow probably, so I think very unlikey we'll play Northern Ireland