[Module] Legendary Potential Rarity

Yes, but have you ever seen an item with 6% on the first line thats rare?
No, you haven't, because getting 6% on the first line of a rare item CAUSES it to go epic.

If it rolled for the lines THEN decided on the rarity based off the first line, you'd see stupid crap like 3% str on the 2nd/3rd line of a unique 71+.

Unless they went and did a roll for the first line, then assigned a rarity then did two more rolls for a 2nd and 3rd line. Which is by far much more tedious than a simpler: roll for rarity, roll for slots.