You both are right.

"there is usually very little difference between the bottom 5 on the A team and top 5 on a B team" is fairly accurate. Every year you see a handful of A players move down or to another club and a few B players move up, that speaks to this.

"The top 5 on a B team would struggle to make an A team that is in the top 5". Well, Top 5 is kinda arbitrary cutoff, but yes, it would depend on what team. If you look at say M&D 2024, about 40% of those kids weren't on that team before miiddle school and the ones who took their roster spots were on teams outside the top-20.