TLDR: Class hierarchies should only be used for truly hierarchical objects, which is rare. Composition is almost always the correct structure. When in doubt, us

TLDR: Class hierarchies should only be used for truly hierarchical objects, which is rare. Composition is almost always the correct structure. When in doubt, use composition. You can almost never go wrong this way. Another way to look at it, by subclassing List, any method that takes a list can also take a Team. That makes no sense. A method that takes a List should take a list of team members.