There's definitely an issue where ships use their centers to calculate distance instead of their edges. I've been meaning to fix that, but it's not trivial because some ships are very oddly shaped and so the distance between two ships will vary greatly depending on their orientations.
Eventually I'm planning on adding much larger weapons for larger ships that have longer ranges.
If you don't know, you can adjust the range at which your ships will attack by either right-click-dragging on and away from the enemy ship, or by holding shift and moving the attack command away from the enemy.
