Baseball card size matters a lot for safety and the best display
Adding in free milling and Army making here is awesome too
While Dreadhorde Twins can provide a quick boost to your board presence with its amass ability and granting trample to zombie tokens, there are potentially better cards like Liliana, Dreadhorde General or Death Baron that offer more versatile effects and synergies with zombie tribal strategies
These cards are specially designed to work best in the digital format
But if the skeleton needed even one card less overhead, such as being able to get by with just one of the tandem of Mana Crypt or Thran Dynamo, it could be done
Here an example of a Pikachu I own with pink borders, but at the top-right it still has yellowish borders: Here another one that was exposed for a longer period of time, making the card overall lighter, and the border more beige instead of pink