I'm unsure where the direct LSX file is, but the file pulled in the stats editor under Shared->ExtraData->Data has a values "AttributeBaseValue" (10) "AttributeCharCreationBonus" (1) "AttributelevelGrowth" (2) among others.
Changing the "attributeBaseValue" to 5 sets all starting attributes to 5. I'll also note that the number you set is considered the neutral zero point such that any points above will start increasing 5% and below -5%. Something tells me you should be careful to not allow negative numbers in a stat field, remember some items and debuffs can reduce stats.
Changing the "attributeCharcreationBonus" however did not give me additional points to spend (tried 10 and 30) in the creation screen nor when I was in game. So you might have to do some more digging there, it may just need to be fixed on Larian's side.
The files you are currently in, to my understanding are primary used as a global modifier to apply traits across groups of units. Such as the lizard and undead sections define specific footstep parameters. Then further down you'll see other undead inherit these traits while adding their own.
