Have you actually read about the SETA tire model and other stuff?
That is the actual problem. It's not the renderer. Maling a smart guess SMS uses a lot of that stuff. AA is basically optional. Well, for PC. So again a guess, they only use post processing AA for Wii U already.
Those Batching and and Occlusion Culling benchmarks where under perfect conditions by the way.
That still doesnt help with to demanding physics and stuff like that. SETA uses a FEM simulation for the tire carcass as well as two other parts. For every tire. That is quite demanding.