L.A Noire was a stand alone built on it's own engine that's only connection to GTA anything was the Publisher.
The rest of those games were on the Render Engine or the RAGE engine(Rockstars own engine), using an engine doesnt constitute it being a mod in any way, an engine is a compiler for your models, assets, scrips, etc that operate within the engines physics.
That's still a grasping at straw level reach there though.
You're talking about a high level publisher funding decent sized game studios, or multiple studios to work on a single game, these games that were also put out pretty far apart with newer engines and better builds, graphics, etc... Which lets be honest, we're all pretty damn good.
Keep in mind, you're not talking about a Dev/Publisher that got their pants sued off for breach of contract for developing a competing game in secret while working for another company, poaching employees, etc. for 40m and had sell out to a chinese company to say afloat while pushing out paid DLC during Early Access, you're also not talking about a Dev team that started work on a promised dlc, that somehow morphed into its own standalone using entirely reused assets, core programming, etc. that incorporated all the bugs, exploits and poorly built foundation while slapping on some plaster and paint to make it look different.
You're talking about Mother----ing Rockstar games and all the studios they employ my dude. They are not even remotely comparable.