I'd also be wary of considering the "5000" thing a scale bar for the map. There'd be very little point in providing a bar that is 2½ grid sides long and doesn't even nicely divide into an integral number of tick marks per square! But if it really is 5000 units per 2½ grid sides, then it's 2000 units per grid, which is amusingly suggestive of the 20 lightyear length of a sector side in the TNG backstage model of things...
If you look closely, the 5000 is next to the little triangle that juts down from the smaller ticks. 6 of these ticks fit in one grid-square. I believe the suggestion was that each tick was 5,000 units and that six ticks = 30,000 units per large square. You're saying 5,000 units per 2 1/2 squares, which would
be rather odd.