Spells Instead of focussing on creatures, you could favor spells
My logic for including both is simply that they are both so strong, noth as cards and within this archetype, they should comfortably win almost all games in which they are not dealt with reasonably promptly making a potential dead card in hand far less of an issue
Sure, Weird Harvest does give your opponents creatures
I like it best in green decks that ramp out a bunch of 5+ cost threats, at which point Ugin lays waste to everything else (the ramp also helps play Ugin at a reasonable time)
Adanto, the First Fort: The token cost is fair because its repeatable
4 Sphere Grid Green Stompy Decks Are Feasting Green and +1/+1 counters go together like blue and being annoying, and Sphere Grid really leans in to the stompiness that makes the colour so much fun