My tuppence;
It's all about getting one thing done and moving on to the next. It has been designed this way.
The vast majority of what you learn will be useless. Some will be downright wrong. There is no such thing as a centrifugal force but nobody told the CAA for instance. The 100 hours P1 required is a random figure. A 50 hour IR course is far too long even for a poor pilot. You will spend thousands of pounds perfecting an NDB hold only to find that nobody does them anymore. Basically, it's a load of bollocks.
But, the best, easiest and cheapest way to get through it is to do as the CAA want. It's thier ball, so to speak.
PPL exams are based on the PPL syllabus. Dedicated PPL books cover that syllabus. The confuser then tells you the questions you're going to get in the exam. Simple.
The ATPL exams are based on a very different syllabus. These are covered by a different set of books. This time it's a web site that tells you the questions your'e going to get. Also, simple.
Just be patient otherwise you'll trip yourself up. Play the game and to try not to be too clever.
You will be required to jump through many rediculous hoops over the next 24 months or so. Do not create more for yourself.
EK
PS
Have you seen the famous JAR ATPL Human Perf Q about smoking?