The confusion matrix is highly dependent on the native language of the listener.
For example, a German speaker once asked me why we pronounce the German composer Bach's name with a /k/, when [bɑf] is clearly closer to [bɑx] than [bɑk]. It's not to modern English speakers. But it might have been closer in Middle English: the word laugh, which was originally pronounced with /x/, is now pronounced with an /f/ and not a /k/.
Similarly, this question and its answers show that Spanish speakers perceive /ɛ/ as the closest English phoneme to /e/, while English speakers think it's /eɪ/.
And I suspect that /z/, /d/, and /v/ are the closest phonemes to /ð/ in various languages, because these are all substituted for /ð/ by foreigners learning English.
And even among native English speakers, people from California can't tell the difference between Don and Dawn, while people from the U.K. think they sound nothing alike.