Aren't they simply called "consultants"?

> Who hires “pure solution modelers”? I don’t think I’ve ever encountered someone like that.

They're called Business Analysts, sometimes simply Analysts, and that's effectively their job - come up with a spec and give it to the software engineers.

I've never seen BAs execute that way. I don't think that is an accurate description of their role and its link to SWEs.

Agreed; typically (especially if a client is involved) I’ve seen creative and dev define and articulate spec and expected behavior, and BA documents it. Then, when it inevitably evolves, BA’s job is to capture the changed spec. The artifact is simply documentation as a client deliverable that’s then often never referenced or used for anything outside of maybe complaining that a feature doesn’t do what the spec claimed, or maybe as context when the client takes their whole project to another vendor to be rebuilt from scratch lol