If you can speak German at the B2 level or better, you interview well, and you know your stuff, you can very probably find an Assistenzarzt position. EU citizenship is not currently required, especially if you speak German well and you are not from a country that causes German immigration authorities to raise an eyebrow. Again, though, that is where things stand at the moment, no telling how it will be in few years. For more details I would recommend contacting a few of the recruiters. Most of them speak at least some English and may even assist in the German classes to get you to B2.
"When I haven´t any blue... I use red."