What is the value-add to this specification that we get by segregating by networks that have a field colloquially called “chain ID”? Networks with a “network ID” (which functions identically to chain ID in this context) don’t count and should get their own top level name (like Morden)? What about when we have two networks that have a chain ID but collide with each other (there is no guarantee that chain IDs don’t collide, you only need to avoid collisions when you have multiple chains that share a network protocol)?
Could we achieve the same goal by saying “any network that has a numeric identifier”? This would at least be a bit more consistent and useful, because it allows us to do some grouping without having to set such an arbitrary group boundary and ensure that the second field is a number.