Keep in mind that these are units AOA and not degrees though (I have never understood what bright idea these units are supposed to be).
Regarding the AIM-9P Sidewinders, I always found them to be perfectly adequate (due to historical preferences, I never fly with the all-aspect AIM-9P5). Since this aircraft requires visual identification of the target, I have never felt the need for an all-aspect missile. When approaching a target head-on, I can’t shoot it because I don’t have a clear ID. I visually ID the target during the merge and then its a dogfight, where any valid Sidewinder shot is from the rear-hemisphere anyway, And shot in parameters, the AIM-9P is deadly. I don’t think the AIM-9P5 or even AIM-9M would change a lot for the F-5E (unless you set up a controlled 1v1 and want to shoot to other guy in the face).
Here is some interesting (at least to me) trivia: During the Falklands War, the Sea Harriers were famously supplied with all-aspect AIM-9L on the way south (up to then they have used AIM-9G). Still, every Sidewinder shot during that war was launched form the rear, from the same position the AIM-9G would have worked as well. I am not aware of any documented engagement during the Falklands War where the all-aspect capability of the AIM-9L has actually been utilized.