P5 Advice needed

Hello Sir, I know P5 is a very different subject and probably the most tricky one in an exam context. The requirement of the questions are sometimes the most important element to understand in correctly approaching towards a reasonable answer. I am preparing to write this paper for Dec16 exam session and I have started with a BPP Revision kit. I work 12 hours a day five days a week in a non accountancy role and I find it little helpful to learn theories for an exams from a study text I find it little helpful or useful especially for passing an exam but still I always buy one. This way of approaching towards ACCA exams has always helped and revision kit is the only book I refer to for an ACCA exam session. I can also appreciate the fact the way P5 examiner approach this subject and set the scenario and then requirements of a questions so I think preparing from an revision kit (and of course in conjunction with opentution lectures notes and ACCA technical articles) will offer me best chance to secure a pass and referring to study texts only occasionally for certain issues. Could you please advice me on my approach and as a background to be very straight with you sir my experience to date is to never fail in an ACCA exam I have just resumed with ACCA studies after a gap of 8 years and and started with writing P1 I could only manage to write on the 70% of the marks available but was still awarded with passing marks and just recently wrote P3 in Sep 2016. I also never ever prepare for more than one subject for a single exam session throught my CAT and ACCA studies. Your advice will be worth a million dollars to me and I truly appreciate your time and efforts in teaching and answering our questions on this forum and I also know it might not be a correct forum to ask this type of question. Thank you.