User blog comment:RayShepp654/How to defeat the Reapers Theories/@comment-217683-20101028230139/@comment-217683-20101029032235

The other Alliance ships were likely scattered throughout other systems, patrolling, in drydock, or just hanging around their assigned stations. They were doing what they normally do. Asking where they were is like asking where were the 30-odd turian dreadnoughts and the rest of their fleet, the rest of the asari fleet, and the rest of the salarian fleet. You can't mass forces to repel an attack you don't see coming. The ships sent by the Alliance were a rapid-response force sent from Arcturus. They were likely all the Alliance could scrounge up on such short notice. Remember, Sovereign didn't exactly call ahead and RSVP the "whole galactic civilization was on the brink of being exterminated" thing. The Alliance military isn't omniscient.

We have canon statements that what we saw at the battle was only part of one fleet (i.e. a small portion) of the Alliance Navy as a whole. We have canon statements that there were no dreadnoughts there. We only have canon statements to support eight ships being destroyed, and eight sounds about right from what I remember of the cutscene. We only saw a few ships destroyed outright. Remember, damaged =/= destroyed. Damaged ships can be repaired.

I agree that the Milky Way galaxy is at a disadvantage, but I think you are exaggerating how great a disadvantage, and doing so without all the facts, as the Alliance fleet bit demonstrates.