Thats still pretty good for artifact decks, and extra mana generation plays quite well with Future Sight effects
Between Traverse, Empath and the Survival of the Fittest Style cards green has plenty more creature tutor stuff than you could ever really need
Mana ramp is a vital component of successful Commander Deck construction, enabling you to accelerate your mana production and cast powerful spells ahead of schedule
Here is the sketch that he did for me
This often takes the form of removal, like Thraben Charm and Will of the Mardu, though some cards buff creatures based on how many you control, like Heidegger, Shinra Executive and Team Avatar
It helps that goblins not only have these but also many other lords and payoffs for staying in type