The kind of z-fighting you get in modern engines isn't the same thing since the zbuffer is per-pixel. The old problem was where entire polygons would draw in front of the other polygon. Now you might get a checkerboard type of z-fighting - it was impossible for only half a polygon to sort badly.
I think what he means is creating meshes to have good triangulation. This means avoiding fans and long thin polygons. Back in the old days polygons were sorted using their centers. Not using a per pixel depth buffer. So you would get something called z-fighting where polygons would 'pop' and draw in front of polygons they…