Heyho,

I've got a base DataObject called "team" and would like to create 2 sub classes of this DataObject called "rugbyTeam" and "cricketTeam".
In the CMS model admin I would like to edit these sub DataObjects.

I've read that you can create DataExtensions but those are not manageable via ModelAdmin.

Any ideas?

Cheers

Ideally, you should call them RugbyTeam and CricketTeam (note the upper camelcase, just a convention thing).

That aside, you could manage these two model in different tabs in a single module admin.
Example:

<?php
class TeamAdmin extends ModelAdmin {
    private static $managed_models = array(
        'RugbyTeam',
        'CricketTeam',
    );
    private static $url_segment = 'teams';
    private static $menu_title = 'Teams';
}