Forces of Nature are nothing like GW’s wood Elves. I can field a Forces of Nature list that is mainly Salamanders, Naiads, and Centaurs… these things were never in Wood Elves. Yes Forces of Nature have the Tree spirit and giant eagles units from Wood Elves, but they don’t have the Elves.
Nightstalkers, may be close to Daemons, but I think Forces of the Abyss has them covered and Mantic are trying to make their unique range stand apart.
Forces of the Abyss have enough units and unit options to cover the 4 Chaos gods model range.