The word "Chance" has a few translations to German: Chance, Zufall, Gelegenheit, etc. The German Chance is borrowed from Latin, where it developed from cadere "to fall". I can assume the word Zufall means also "to fall" (because that's the literally meaning of the word, if you break it zu-fall). So the existence of multiple words for the same concept definitely show some cultural exchange of the people speaking the language.
My question is can synonyms be used to show (or speculate) merges of ethnicities/tribes, etc? And are there any prominent examples of this?
EDIT: maybe a more concrete example are the words Lage and Schicht(ung) in German, both can mean "Layer", but the first origin is from Old High German, while the 2nd is from Old Low German. Could it be that some people used one word, other people used another, and with time and cultural exchange, both people started to use both words?