It is well known that ancient Greeks such as Herodotus thought other culture's gods (e.g. Egyptian) are actually same deities as theirs, just having different names.
For example, Plutarch said
Not different gods for different peoples, not non-Greek and Greek, not southern and northern gods; but just as sun and moon and earth and sea are common to all men, though they are called by different names by different peoples, so of the Reason (Logos) that orders all things, and of one Providence that also directs powers ordained to serve under her for all purposes, have different honours and titles been made according to their laws by different nations.
As I quoted above, there are many evidences that shows Greeks thought other gods are same as their gods, and by doing so they syncretized other culture's mythology.
But basically, all ancient polytheism was not exclusive, so I believe not only ancient Greece (and Rome), but also other cultures had a discourse used to interpret or attempt to understand the mythology of other cultures by using their own mythology, so-called "interpretatio OOO".
I know that there is "Interpretatio germanica", but it seems it was not a dominant practice compared to the Greeks'(and Roman's).
Simek emphasizes the paucity of evidence for a widespread interpretatio germanica, as opposed to the well-attested opposite interpretatio romana, and notes that comparison with Roman gods is insufficient to reconstruct ancient Germanic gods, or equate them definitively with those of later Norse mythology.
Q. Why is this phenomenon prominent (or 'seems too prominent') only in Greece among other polytheistic countries? For example, why we can't find such records (or 'can find only few evidences') in ancient Hinduism? Why there is no word such as "interpretatio China", "interpretatio Egypt"..etc?