The rule book is missing the following text concerning this card:
"Similar to Interstellar Battle, when the Arbiter causes a battle among players, any player who defeats an opponent's flagship, may move one of that opponent's allies with the lowest mission points among that opponent's allies to their points area."
Thus the battle caused by the Arbiter can change the outcome of the game.
Also to better explain the Arbiter's GOAL, it should be read as follows:
"GOAL: 2 or more Ally Starships then all other teams AND 200 or more mission points. Any team can complete this GOAL."
The clarification is that you don't need 200 or more mission points then all other teams.