For examples of how little a team’s form in the World Cup run-in matters in the tournament itself, look no further than the US
The last time the United States men’s national team entered into the home stretch of its preparations for a World Cup on home soil, the results were dire. From January through April of 1994, the Americans, who were mostly sequestered in a full-time training camp, played 12 games and won just twice. They even managed to lose to Iceland, a total non-factor in global soccer back then.
Then, that ’94 incarnation of the team went on to survive the group stage and narrowly lose to eventual champions Brazil, 1-0, in the round of 16. They delivered on expectations in spite of their deflating run-in.