You're missing the point. The age requirements are different for the US Lacrosse tournament. That allows teams to bring in players, due to their actual birth day, from the older age group to play in a younger age group. US lacrosse is not about players from the same birth year. YJ did it last year with their 2021 team. They brought in a all star player from their 2020 team, that met the age window, to play with them. Other clubs do it too.