Ok, I know in the third game USA had an amazing aoe team comp compared to Europe. However, I don't get why Europe managed to lose every team fight, and in the end were afraid to even initiate.

To land a perfect aoe combo like USA did consistently usually requires a lot of luck or the enemy team to just be really bad. Is it just me or did Europe just have no idea how to team fight USA and failed positioning? (I know their 4 squishies on the team definitely contributed, but they still had a Janna who is the amumu killer...)

europe isn't at good at teamfights as CLG, and after that first ace the game was just a steamroll because of being outplayed and outgeared