Does it make sense to develop a fantasy sports management system by creating or extending entities? I am considering building a fantasy sports management system with Drupal. The system will need content, so that's taken care of with the standard Drupal system. However, does it make sense (or even possible) to create new entities that represent players, teams, leagues, stat-lines, etc?

I have built systems like this in the past (.NET) and it's difficult for me to wrap my mind around the idea of combining content nodes with players, teams, and stats. There are many fields that are exclusive to each type of node/entity and the sheer volume of players and stat data will push the node tables to crazy levels.

I haven't messed with Drupal 7 entities (which I believe abstracts nodes, users, and taxonomies), but I'd like to hear opinions if this concept is possible.
Drupal 6 has a module called League Site that might be useful to have a look at... I don't think it has been ported to 7 yet but it has an awful lot of functionality for league sports right out of the box.