Polysurfaces, surfaces, extrusions, meshes and SubD objects all work as input to Zebra in Rhino V7
https://docs.mcneel.com/rhino/7/help/en-us/index.htm#commands/zebra.htm
Some shapes can be modeled as a NURBS polysurface but not as a single NURBS surface. Some shapes can technicaly be modeled as a very dense single NURBS surface but are very likely to have problems.
Your final helmet shape with the ribs and holes is a shape which perhaps could be modeled as a very dense trimmed NURBS surface but the results are likely to be unsatisfactory for most uses.
All untrimmed individual NURBS surfaces have four sides. One, two or three sides can have zero length. A NURBS surface can be trimmed including with holes but the underlying surface will still have four sides.