On the Contrary - The Newland City Council did just that. However, The Reason Omni-Tek is in Borialis is because there was nobody else that was stepping up to guard the city. And as at the time it was a prime target(and still is, due to the oversized dish sitting on a hill high above the city) there wasn't time to allow the nuetral peoples of Borialis to muster theyre own security force - A process that would have taken months, weeks, even years to accomplish, which by that time the Aliens would have come in anyways. Also, in case you have never looked at the "Omni-Tek Forces" at the dish itself, it amounts to a few unicorns. Omni-Tek's occupation of Borialis is to provide added defensive forces to the Dish, as well as to protect the peoples of Borialis from the Kyr'Ozch Threat.