apparently they were suppose to be the og borg, by gene roddenberry hated the idea, so they created the borg instead. they were suppose to be a much wide ranging foe. Hence the part where they sent the signal to delta quadrant, which in enterprise show they did the same thing, indicating they were suppose to a larger arc than they were, probably have a large empire(much like the borg)

gene just hated the concept.

sg1 was just that, parasites controlling the hosts, and have a large interstellar empire(we know sg lifted material from trek quite a bit)