Surname derivation from the Angle tribe, once based in northern Germany, is unlikely.
1. The highest concentration of Angloher residents of Germany per Geogen is in south-east Bavaria, near the Austrian border. An origin in local vocabulary is most likely.
2. The word ending "er" implies belonging to or having connections to something or somewhere. As it happens, there is a placename "Angloh" not far from Bad Füssing in the high concentration region identified in point 1.
Angloher most likely derives from "the man from Angloh."