With the way the map generation works, there is never going to be perfectly equal distances between nodes.
If there is too much imbalance in Cygnus which is leading to an unfair advantage, then it might need to be removed from ranked play.
Pros to bottom position:
The bottom position has 1 less node to travel to the central node.
The bottom position has 30% less distance to the central node.
(The central area is metal rich, which can be very beneficial to get control of it.)
Cons to bottom position:
The bottom position has 20-60% greater distances to travel for the starting 3 nodes.
The bottom position has 3-10% greater distance to the Computronium (Turinium) generators.