Brazilians and Argentinians can watch a match in the same room.
The Dutch and Germans have some obvious history, football and otherwise...although I'd say the latter has cooled down over the years.
But the Argentinian and Brazilian football rivalry is something else. Both sets of fans derive significant identity from this sport, particularly against one another. This is Messi trying to equal Maradona and surpass Pele, as Argentinians see it. This is, in the Brazilian perspective, Argentina trying to take what's rightfully theirs, pushing yet another imposter to wrongfully supplant King Pele.
That's the match where I could see fans having a serious go at one another.
I just see the German and Dutch players trying to break one another's legs, while at least the Brazilians and Argentinians would try to outplay each other -- it would be about football.
For the Germans and Dutch, it would be about football, but not really, and the losers would get it rubbed in their face for a generation.
If they do make it to the final, the prospect of winning or losing the world cup would be a good thermometer for how much "cooling off" has really happened between them.