Fe-I: I think the z-axis (arrow pointing up, I imagine the x and y axis being perpendicular to this arrow) is a 4 fold rotation axis, while the x and y axis are both a two fold rotation axis. This means that the z-axis can be the z-axis of the PAS and that there is axial symmetry.
Fe-II: I think the x, y, and z axis are all a 4 fold rotation axis, so the EFG is zero here.