Among these dark wizards, there is no shortage of talent.
Let's put it this way: if two identical wizards were placed before Elwin, and Elwin had to choose one of them to take as a subordinate—one of them being a Hogwarts graduate with a proper, orthodox education, and the other coming straight out of Azkaban—Elwin would choose the one from Azkaban without the slightest hesitation.
On one hand, their strength is formidable! Anyone who becomes a dark wizard and gets locked up in Azkaban has broken the law. People like that definitely lack no shortage of actual combat experience.
Chapter 448