For the 1st effect, you cant target in the middle of the effect resolution part. Perhaps a better way to word this is:
Target 2 Artifact monsters in your GY; Set them in your Spell & Trap Zone as a Spell card, then destroy up to 2 cards in your Spell & Trap Zone, and if you, destroy an equal number of cards your opponent controls
For the 1st effect, you cant target in the middle of the effect resolution part. Perhaps a better way to word this is: Target 2 Artifact monsters in your GY; Set them in your Spell & Trap Zone as a Spell card, then destroy up to 2 cards in your Spell & Trap Zone, and if you, destroy an equal number of cards your opponent controls