There are dozens (maybe even hundreds) of human cultures that existed at the time Homer was writing, or when Gilgamesh was written, that also have no equivalent.
The idea that any roughly equivalent human culture will develop the same things is clearly wrong. Just look at the plough - for centuries or even millenia, humans outside of what is now China had ploughs but failed to gain the insight to improve it in the way it was improved in China. Once trade exposed them to the Chinese plough, it was more or less universally adopted within decades.
While multiple (re)invention may be common, it is not universal. Just because culture A manages to find is way to cultural/technological innovation doesn't imply that culture B will, even if the two cultures are very similar.
The idea that any roughly equivalent human culture will develop the same things is clearly wrong. Just look at the plough - for centuries or even millenia, humans outside of what is now China had ploughs but failed to gain the insight to improve it in the way it was improved in China. Once trade exposed them to the Chinese plough, it was more or less universally adopted within decades.
While multiple (re)invention may be common, it is not universal. Just because culture A manages to find is way to cultural/technological innovation doesn't imply that culture B will, even if the two cultures are very similar.