Jonathan Lee Miller (AKA Jonny) is an English actor who gained notoriety with roles in Hackers and Trainspotting. The son and grandson of Stage and Film actors, Jonny's first (uncredited) role was at age 10 in an episode of Doctor Who. In 1996 he married Hacker's costar Angelina Jolie, divorcing just 18 months later. He later married and had one child with actress-model Michele Hicks.
Bit of artistic license here. What if Good omens was a BBC miniseries, 3 years before the actual book and using some of the crew that used to work on Doctor Who, hitchhiker’s and the like back then, and using the template of the Amazon series.