Because issue of the ATPL also issues or renews an Instrument Rating, many of the questions and flight test profiles are the same as an IPC.
But there is more to it. The ATPL requires a good understanding of AOC requirements, more emphasis on multi crew procedures and CRM, and one in-flight problem is left to the complete imagination of the examiner. The so-called surprise event.
Pilots coming from an Australian single pilot GA background will answer most of the oral correctly because they have heard it all before. They usually do OK with the handling exercises, but often come unstuck in flight management.
Pilots coming from an overseas multi crew background often struggle a bit with the oral, but make up for it with superior flight management. This is somewhat of a generalisation, but a trend nevertheless.