That is a great point Sturgis that those who speak English also pronounce words differently.
I think of how different British English is spoken from US English and even the differences within each type of English.
About optical illusions, one illusion is when we look at the stars in the night sky.
Some are small yet represent galaxies not stars and some are large and represent a small (like our moon) rock and have no light of their own compared to our sun that appears the same size as the moon.
Many of the objects we see in the sky are long gone as it has taken millions of light years for the light to travel to earth. In that time they may simply have decayed and dissipated into space dust.
The sun appears as if it is circling the earth rather than the earth spinning on its axis. It took thousands of years to dispel the flat earth theory as some foolishly still think it is plausible.
How grandiose optical illusions are comparable also to illusions of our own historical past.
To dispel a theory without proof is just as closed-minded as believing in a theory without proof.
The theory of how religions spread from one central place throughout the world does have an enormous amount of credence.
Just comparing the Greek and Roman pantheons, one would have to be totally blind to not see the vast array of similarities. These similarities are also present when comparing other polytheistic religions.
Are these similarities proof? No one similarity is proof on its own but when a wealth of similarities are observed then we uncover a "system" of proliferation. This system seems to use the very same vehicle that words use to travel from one language to another.
For instance the word "king" is rex in Italy, rey in Spain, rik in Norway and Germany (even though the languages are different), roi in France, raj in India, reg in Britain, ra in Egypt.
Now just as the word king has leap from one language to another, customs and religious myths have also crossed the very same barriers, maybe even to a greater degree than words.
Is it merely an illusion that these words for king are so very similar that they are spelled differently because of the various ways people hear or are able to pronounce words in their own dialects? The word for king in China is Wang... is this a derivative of our own word king in English?
Just as a god of war may become a God of the arrow in one culture and God of the sword in another they still bear the same warlike persona.
When all of the similarities are calculated we see a pattern of spread from one source (Mesopotamia) to another, from the Greeks to the Romans and onto all pagan systems in contact with one another.
The Romans conquered nearly the known world and this may be the main influence of the world "rex" traveling to other cultures.
But we also see similarities in words like mother and father and types of foods, mathematical and science words and words associated with trade.
Why would not culture also be exchanged in myths and stories of rulers and Gods?
Indeed the vast array of similarities in myths are present when we compare religious systems.
Much like the Zodiac which is present in many cultures it carries similarities down to the very star names such to the degree that it is nearly impossible to tell where it actually originated.
"The classical map of the sky, with the 48 Greek constellations, was derived from at least two different pre-Greek traditions. One tradition comprised the 12 signs of the zodiac, with several associated animal constellations, all of which developed over 3,200-500 BC in Mesopotamia in a religious or ritual tradition."
The Origin of the Zodiac
Some may want to argue where the Zodiac originated from but, it seems if it can proliferate and become associated with so many pantheons of different systems of Gods and Goddesses and the stories that accompany them then, we can easily surmise that a lot more intercultural exchange was occurring than that which is thought by many.
The ancients were spreading their polytheism and cultures far and wide. It would only take one person knowledgeable in any particular system to spread an entire religion to another similar culture with the same predilection to adopt polytheism.
Wandering travelers much like our missionaries of today would certainly have considered their own religion the "good news" of their time. Much like people who cannot help themselves to wish others "Merry Christmas" knowingly to those of other faiths
With the preponderance of evidence we can rightfully conclude that religious intercultural exchange was much more than an illusion but it was a rule. Paganism did not sprout up independently but it evolved with the spread of monotheism from culture to shining culture.
Therefore paganism and polytheism they can be seen as one religion rather than many varying regions such that when one chooses to pick one as a favorite they are in actuality picking all of them.
Underneath the various "seemingly" different stories is the exact self-same mystery religion.
All roads lead to Babylon...