Well, you'll either need to collect the cards from Arena booster packs for the sets they came in, or else directly 'craft' the specific cards you need using MTG Arena Wildcards - effectively tokens you can exchange for the exact Common, Uncommon, Rare, or Mythic Rare card you want, depending on the type of Wildcard
Especially in cases where cards are rated similarly elsewhere, this factor will favor the card thats doing something a bit more off the beaten path
House runs the casinos of the New Vegas strip, so take a gamble with him and see if you can roll big and build up your army of Securitron robots
Theres a ton of support for an artifact deck in the format right now, in blue especially
The Council of Four Cards that profit from your opponents taking game actions scale very well in Commander
It won't be put on the remaining legal target instead