Like Rumsfeld says "You go to war with what you have, not what youd like to have"
Charles Trip Tucker III said:
I was speaking from the Borg's perspective, not that of the audience. You would think if one ship wasn't enough, you'd just send more... not go back in time and screw with history.
To this day im not sure if the Cube was the primary threat or if it was just acting as a carrier and the sphere was the primary threat.
The thing is, VOY revealed that the Borg have hundreds if not thousands of ships. Surely the Collective could spare more than one?