Here be the Arena teams. (Patreon)

In order are the:
The Guardians. The team that was supposed to be in Daggerfall when Arena was still considered to be an arena game.

The Dragonlings. The not as popular team you first join as a player.

... nameless guys ;P These are the runner ups, the rivals to the guardians.

This love triangle of teams will allow to do some drama questslines and smaller quests. Perhaps you'll be able to join either of the better teams or choose to lift up the Dragonlings instead.