Yes, they technically have a mana value of 0
Its quite in character for Sauron to dispose of their minions, sending them to attack and deal the most damage possible while sacrificing those that would already die anyway
All the support for land strategies in Golgari comes from green which is a surprise to nobody
Appendix My first deck was built around Alora, Merry Thief and Far Traveler
1 Underground River 7 Swamp 7 Island 1 Tamiyo, Inquisitive Student 1 Nethergoyf 1 Cecil, Dark Knight 1 Sinkhole Surveyor 1 Caustic Bronco 1 Dauthi Voidwalker 1 Gix, Yawgmoth Praetor 1 Preacher of the Schism 1 Emet-Selch, Unsundered 1 Fallen Shinobi 1 Shriekmaw 1 Cling to Dust 1 Portent 1 Ponder 1 Consider 1 Inquisition of Kozilek 1 Bloodchiefs Thirst 1 Stormchasers Talent 1 Heartless Act 1 Sheoldreds Edict 1 Long Goodbye 1 Winternight Stories 1 Stock Up 1 Control Magic 1 Snuff Out It looked great there when it was played
Just draft, add lands, and play