It's not actually irony, it's a coincidence.

??? I don't understand why someone wouldn't regard the "Jr." part of Bela G's name as "legal." I don't think "juniorness"--that is, using the term "junior" is a legal concept in the first place. If his parents named him Bela George Lugosi Jr., that's his legal name, no matter what Bela Sr's original names were. Issur Danielovich's sons' last name is Douglas.