Using cardinal directions really isn't a strong feature of the language though is it? It's secondary to the language itself and any culture could do that with their own language because it isn't a central feature of the language. It isn't in the grammar. Which makes it not an example of strong Sapir-Whorf but an example of weak Sapir-Whorf. The former is all token adult claimed and the latter is something that is, I think, more accepted.