I was finally able to workaround this by using glDepthRange instead
// Draw underlying geometry
glDepthRange (0.1, 1.0);
drawPolygonFace();
// Draw overlying geometry
glDepthRange (0.0, 0.9);
drawPolygonWireframe();
This deals with the need to draw coplanar geometries.
More details here :
https://github.com/jzy3d/jGL/issues/3