Artifacts are among the hardest permanents to remove (with some colors unable to remove them at all), so Chocobo Racetrack is likely to stick around once it hits the battlefield
The cost reduction applies only to generic mana in the total cost of spells you cast from your graveyard
Alternatively, you could play Sheriff of Nottingham, Corrupt Official with Simba, Fighting Prince - whose ability, Step Down or Fight, gives players the option to draw two cards and discard two cards whenever they banish another character in a challenge, or The Queen, Disguised Peddler, which allows you to tap it to discard a character to gain lore equal to the amount of lore that character can gain
Dont be afraid of the card disadvantage
Turbo Royal Hack and Snowanna Rainbeau Cool Competitor can take out 2 Willpower characters in those early stages
The fact that its not an artifact might hold it back too much in the end, but I dont think this is bad by any means