What is the connection between Greek and Egyptian mythology?

I have been starting to think that they are strangely connected like how Horus and Ares or Mars are sort of the same, the god of war. I could understand that and how Ra could be like Helios because he WAS the sun god. I was also thinking of the strange connection between Osiris and Hades. Osiris is god of the dead, and Hades is god of the underworld. So are they connected and IS Horus and Ares connected and are Osiris and Hades connected???