Artifact Question : Primary Stats

I started a new Save File and so I have been paying more attention to Artifact drops.

When I find a Sword or Necklace in the Realms (loot) sometime I get a +22% Attack (or Intellect) bonus and sometimes I get a +30% Attack (or Intellect) bonus.

Is this the intended behavior? (I have never found any value other than 22% or 30% … This seems odd. It feels like either they should all be the same or else they should be random. Having exactly two options seems weird)

I believe artifacts were changed up a bit a while back so that that enchantments they naturally generate are capable of being more powerful than the enchanted stats you can place on them.