I don't think that's correct. He thinks that a team IS a group of players. Just like a list IS a group of items. team.players.count is like list.items.count

I don't think that's correct. He thinks that a team IS a group of players. Just like a list IS a group of items. team.players.count is like list.items.count But that's a small point, in general I agree that he should not be inheriting from List here.