They are just pointing out that the database entries for the mods are wonky af.
0.000 modifiers for instance
as well as there being no base model for the guns
Both ATAC Ntec and Ursus should be 50m for damage dropoff start.
ATAC and Ntec both hit 30% damage by 70m, but Ursus gets to 75m before 30% due to not having curve mechanics.
ATAC however is less useful at even 50m due to lower min accuracy, and CJ only makes that worse.
Well since you already know the stats, I wont bore you with the math.
The tl;dr is the ATAC is easier, the Ntec and Ursus are more accurate and more versatile.
Good players use ntec, lazy players use ATAC.