Take this with a grain of salt...
CT: SCOUTS mandated that if you had a world with an atmosphere type 4-9 OR Population 8 for main world, the 2d6 roll for the primary star type was supposed to be at +4. If you look at Megatraveller's rules for generation primary stars of any pregenerated world (which all of the Spinward Marches were by dint of being published as supplement 3 by the way), you would find that the rule is the same: roll 2d6 and add a +3 modifier.
Of those systems in Spinward Marches, there are 439 star systems. Of those, only 264 meet the requirement that the planet has an atmosphere 4 to 9. In addition, there were also another 25 that met the criteria of population 8+ but not the atmosphere type. That's a total of 289 star systems that should have had a +4 modifier on the 2d6 roll for star type. That means, that the minimum roll would have been a 6 and the maximum would have been a 16 on 2d6.
When you look at the statistical results - you'll find that only 8% of the star systems that meet the criteria of atmosphere 4 to 9, or population 8+ should have an M spectral class star. The spectral class A should not even be possible, as you need to roll a 2 on 2d6 unmodified. The modified roll of 2d6+4 should make a roll of a 2 impossible. Yet, the new survey has 29% of all those stars as being M class spectral types. Per the rules given in either Scout or MegaTraveller's Referee book, the bulk of the stars should have been K class. Instead, the breakdown is as follows:
M: 85
K: 65
G: 69
A: 1
F: 69
Clearly, when someone wrote the program to spit out the results for the Spinward Marches data, they sort of didn't follow the rules as given.
In addition, there are a lot of worlds that have a diameter that is too small to even retain water vapor - let alone water, which is why some of the worlds need some serious tweaking in order to have them make more sense. When I used to hang around Citizens of the Imperium - there was a discussion on why some of the worlds data were different than the canon values, for much along those lines.
Me? I'm awfully tempted to go back to the original data, use GURPS SPACE to generate the actual stellar data for the star system, and leave it at that - my own "In my traveller universe" instead of using the stellar data from the other stuff.
That's just me however, and generating 439 star systems by hand is a royal pain in the arse - writing the code would require that I actively sit down and code, which these days, I lack the determination to see to the end.
Then again, T5 had good advice: MOAN - Map only as Necessary. That also means "Generate full data only as necessary."
