The Greeks assumed the Egyptian gods were the same as their own gods, but in different form. The early Greeks accepted that the Egyptian gods were their gods, merely having different names and appearances. Many gods were given Greek-Egyptian hybrid names in which the reason isn't 100% known. Some believe it was to please the local people of the tribe or village they were living in so no conflict would occur and others believe it was because the Greeks believed that their gods were so powerful they could show many forms and be in many different places at once.
I hope this helps:)
