The remainder of the cards are designed to facilitate consistent openings, ensure your effects resolve, and answer meta threats
Farideh, Devil's Chosen is also an interesting payoff, allowing you to draw a card whenever you roll a 10 or greater (the base die is usually a d20, mind you)
Event provenance: Tournament-only releases add a layer of prestige and documented rarity
These effects call under two broad categories: cards that return lands from the graveyard to the battlefield as part of a spell or activated ability (Tato Farmer, Splendid Reclamation) and cards that allow you to play lands from your graveyard (Crucible of Worlds)
To double the probability to around 32% , you would need at least 19 artifacts
It's also great that the art takes up the entire card with the Ditto closest to the center, so it doesn't turn into a guessing game of which Numel is Ditto