Its just really hard to get a land into the graveyard from the battlefield without effects like Strip Mine and Zuran Orb
You can get a foil Rin and Seri, Inseparable at your local store with each purchase of a Draft Booster display box or Collector Booster display box (while supplies last)
Multipurpose Creature/Ramp A good ramp spell for a green and white token deck could be including a copy of Jaheira, Friend of the Forest which lets each token creature tap for green mana
There is also the risk of it helping Reanimator decks, but is it even as good as Careful Study
Thanks to having access to black, Golgari has plenty of the best sacrifice outlets that let you do so for free, such as Viscera Seer and Carrion Feeder
It's also a great tool for tuning existing decks, uncovering potential flaws in your deck that you can improve