Greece may not have a big chance but we are talking about the national team that has the latest MVP of NBA, lets not put that aside, if the teams go head to head or even close for long enough then Giannis may just go berzerk and finish the game for his team, I am not saying it will happen but having a player like that would make any team have a slight chance of going all the way.
Greece has some good players as well in their team.
It is doubtful that Giannis is by far the best player in the World Cup and he can win a lot of matches by himself for Greece.
On the long term as the fatigue intensifies, he would be able to beat stronger teams. I expect Greece to climb high on the ladder.