I like both Forest Gnomes and Rock Gnomes.
And I see how they are one unified people, too.
But I also see how Rock Gnomes are really just Dwarves that chose size small, and Forest Gnomes are really just Elves that chose size small, but instead of including that size class option in the Dwarf and Elf sections, they created a separate unified section. Similarly, Halflings are just Humans that chose size small.
But you don't want to otherize any player by saying in order to be size small, you have to be a magical non-human person. So Humans now can be size small, whereas if you say you want to play a keebler or christmas elf, the DM says, okay but you're not actually an elf, you're a gnome.
Halfling had this weird identity crisis where the Stout was kinda Half-Dwarf, Half-Halfling, and the Lightfoot was kinda Half-Elf, Half-Halfling (This dates back to Tolkien where Stoors are more Human-like, Harfoots are more Dwarf-like, and Fallowhides are more Elf-like). Like, D&D knows what a Human is, what an Elf is, what a Dwarf is, and what an Orc is. But the other peoples all had a version that was kinda elf like and kinda dwarf like or else kinda human like and kinda orc like (say, Hobgoblin vs Bugbear, with Goblins being kinda Halfling or Gnome like).
But somehow, 1D&D was able to unify Halfling into their own people. But Gnomes are still caught in this limnal space between Dwarves and Elves as their littler variation. Which is weird because Dwarf also means little person in common parlance, so really Dwarves should be able to be small, not one of the only PHB lineages that CAN'T choose Small.
The lack of Ability Score bumps should give room for the two lineages to be merged. Let Forest and Rock be cultures. Svirfs can be different in the way Duergar and Drow are, and by removing Rock Gnomes as separate from Forest Gnomes, you end up with Svirfneblin contrasting more with Gnomes in general.
