I never said it had to be completionist, I said it needed an internally consistent system for determining where Lores fit for the game as is . It doesn't say that the type of Lore is subjective either, it just presents them as is. We are in the Rogue Trader forum, so I'm referring to those lores as they should appear in RT.
So if I wanted to put a lore in about manufacturing, would it be a common or scholastic lore based on the RT rules? Consider that Imperial Creed and Navis Nobilite shows up in both of them but none of the others do. How do I know if Manufacturing is close in concept to Imperial Creed and Navis Nobilite or beasts/adeptus arbites to determine if it is a common lore, scholastic lore, or both? Posters have already said that not everything needs to be in all lores, yet I've yet to see a method for ascertaining what lore(s) are worthy to fit in 1, 2, or 3 Lore skills and what aren't, beyond personal opinion (I'm right and you are wrong). Personal opinion is a bad way to run game mechanics.
I bet if you created a list of new Lores spread across common, scholastic, and forbidden and posted them up others would disagree because it's being based on opinion rather than a concrete guideline.
And thus we come around in a circle yet again. The rulebook does not list its Lores in a consistent fashion because the same types of lores fill both common and scholastic. So what's the difference between them if they both possess the same spread of lore types?
Hellebore