The first artifact turns discarded cards into 2/2 Rogues or Treasures, while the second banks those cards and then returns them to your hand
One of these locations in play may not be much of a threat, but having 2 or more can definitely apply pressure on your opponent to address the issue
First, it's on auto-pilot
Thisll see play in multiple formats, so its more of a question of how much play itll see
9 Nemata, Primeval Warden Graveyard shenanigans are one of the most common sources of sudden, unexpected defeat in Commander, and Nemata gives you a great way to circumvent these with his passive ability, exiling creatures under your opponent's control rather than letting them rest easy in their graves
This means that abilities that trigger whenever a creature attacks won't trigger when it enters the battlefield attacking