Ehh, I have a feeling Argentina will pull it together against Nigeria. I didn't watch the first half, but Nigeria wasted a ton of chances in the second half by just pulling the trigger on shots outside the box. If they had made a few extra passes, they could have scored 6. And I don't think I'm exaggerating.So, if I am reading this correctly, Argentina need to beat Nigeria by 2 goals or more and hope that Iceland does not beat Croatia.
If Iceland does beat Croatia, and it does so by the same number of goals that Argentina beats Nigeria, then Iceland advances. If Iceland beats Croatia by two goals or less than the amount by which Argentina beats Nigeria, then Argentina advances. If Iceland beats Croatia by one goal less than Argentina beats Nigeria, then the goals scored tiebreaker controls and after that the disciplinary tiebreaker.
All of this is just a theoretical exercise anyway, since there seems very little chance that Argentina can get its act together enough to do anything but lose.
I don't think Argentina will lose to Nigeria, but Nigeria could perhaps hold on for a draw. Which would keep Nigeria ahead of Argentina, but brings into a play of Iceland beating Croatia by 2 or more goals.