Although some email harvesting is done by actually, well, harvesting emails, much of it is done programatically. To shorten a very long story, proven good email addresses have the highest value. At a lower level, if for some reason bloggs at testdomain1.cem is found to be valid, then bloggs is tested against all other domains in inventory. Similarly, testdomain1.cem is tested against all other names in inventory. The logic is that there are going to be many people on the planet with the same username, and a domain is likely to have many users.
oxenos isn't a rare name at all, so I'd imagine your email address was generated as a semi-random pairing using the above method. In your case, I'd guess the source user was German or Greek.
The reason that washed lists are way more valuable than unwashed lists is not that the recipients are known good, per se, it's because the emails are more likely to evade ISP-level spam filters.