Not sure which wiki link you're looking at but
this wiki page has a nice table outlining all the architectures and instruction sets.
R700 was when they started the small die strategy with the 4850/4870/4870X2. Evergreen was the successor and continued the same strategy but with larger dies (256mm > 334mm) with the 5850/5870/5970. Then came nothern islands which was VLIW4 for only the 69xx but the other models were rebrands of Evergreen. There was also a naming change, with 5870 effectively being replaced with 6970. All of these architectures used the Terascale instruction set with slight modifications depending on the iteration. They were all very successful too, especially the 5xxx generation.
Then Southern Islands came along with the HD 7xxx's and all used the GCN instruction set for almost the next decade. Heyday of GCN was the 7000 and 290x launch times when they were much faster and had a better/more forward looking arch than nv at the time. Polaris was released after a few years when GCN was long in the tooth and was a small die priced cheaply to tide them over till RDNA. They did release two more flagships though with HBM of which the last GCN, Radeon VII, was the pick of the HBM bunch and a swansong to the first arch AMD designed after taking over from ATI.
