What does semi-random even mean on the Anvil Stats ?

I have played 50+ games at this point and whenever I run Shareholder and I buy Anvil Stats it is the same thing 95% of the time.

If I get two """RANDOM""" Stat Shards at value 150-200% It is guaranteed to be the opposite of what my champion uses, If I am playing an AD champion it is either 2 magic penetration shards or 1 magic pen and ability power shard, or If Im lucky enough one of the shards will be magic resist shard, and once in a blue moon there is a chance for it to be something like Ad/As oe Lethality.

If I play AP champion then it is Lethality/Ad or Lethality/Ad and Armor, so the question is what is semi-random even supposed to be, because from my experience it is just Rito Games trolling people, I almost never got mostly the stats I need for the champion I played, so naturally the best picks I think for Stats Run are champions like Xin Zhao, Kai'Sa, Jax and other hybrid champions who can use all stats because apparently """semi-random""" stands for go f*ck yourself...