The JOE is more about collecting competencies and not so much about getting "hours". The assessors seem to like to see at least 3 entries in each competency.
It does seem a little over complex but seen 4 apprentices deal with it now.
The old SOE system had some quirks . Like gaining 100 hours in turbochargers, 50 hours in radar system or 50 hours in Rad Alt . Almost impossible!
The four year restriction I haven't heard about?