Almost correct
It's a team that is painted by different members of the TBB community. We agree on a race and a color scheme, then everyone who wants to participate paints one mini. One person collects all the minis, makes some team pictures and then one of the contributers is drawn randomly and wins the team.
The first 2003 TBB team was a gobbo team, 14 painters, won by McDeth:
viewtopic.php?p=88611#88611
(missing Anthonys and Lightning Bugs minis)
The NAF forum has started a legacy team as well (Vampires, finished in Nov. 2003) and TBB is going to have a second legacy team (Slannesh Chaos, deadline end of January 2004).
Because of coaching staff, cheerleaders, team variants, etc ... its not a big problem to have 30+ people working on a team ...
There's no agreement that the winner has to play this team at the Blood Bowl ...