I suppose Ronaldo has been 90% of the team so far... But, they have been playing only with 2 or 3 players to pass the groups' stage.
Actually they have some standout awesome players, who are still warming, like Gelson, Andre Silva, Quaresma or even Bernardo Silva from Man.City (who've played a complete zero so far). Anyway, keep an eye on that strong team to come.
As for Argentina, I believe is 100% Messi, and if he's not in top shape they will struggle a bit.
As for Germany and Brazil, one way or the other, I believe they will reach quarter/semis at least.