Dredd's bio would fill a book I suspect.
Re Vol 2 ~ I found a lot of the bios rather thin, often missing important events or quirks of character mentioned in the comic strips. Often the brief text concentrated on a crime or aspect of Mega City One rather than the Judge him/herself. No great problems , though I suspect this will seem a tad wastedful if they are repeated in further volumes.
Novels seem to have been ignored for reference material but the audio books have been used.
Good choice of Judges I felt, though I would have preferred Votten was put in perhaps instead of Steel .
Choice of Kruger was surprising , seeing as his printed, history is at continuity odds with the Sector 13 background material and scenarios being run by Mongoose.