I included that comment because I think a lot of people jump into P&D a little early in their marathon careers, and may not make it through the plan, never mind the marathon itself. It's not that it's particularly difficult, more that it assumes a certain level of base mileage and experience. The clue is in the title. It is not a beginners plan. It could be an improvers plan, but not until they have two or three successful marathon cycles behind them, in my opinion.
I was going to suggest the meno plan for you, but I see you've already come around to that way of thinking yourself. The flexibility is good for people with odd schedules. And it has some great sessions that, in my experience for marathons 2, 3 and 4, really helped me to understand what marathon training is all about - something you can then take into a plan like P&D. Meno designed the plan specifically for improvers and it's worked for a lot of people around here - in my case helping me get down to sub 3:30 from a 4-hour-plus debut.
Reading down through the thread I realise I haven't laid out my own PB's or marathon progression:
5k: 19:58 (06/16 - Clonpriest) - had a 5k split of 19:47 in a recent race though.
10k: 41:28 (04/17 - UCC Carmel Lynch)
10 mile: 1:08:53 (03/16 - Ballycotton)
Half: 1:31:52 (09/16 - Charleville)
25k: 1:50:32 (04/16 - Great Railway Run)
Dublin 2014: DNS - Injured by August, out for 6 weeks - too much, too far, too soon.
Cork 2015: 3:49:29 (Used a MyAsics plan - 4 days a week with the odd race as well - ranwell, with a negative split of nearly 10 minutes or so)
Dublin 2015: 3:38:39 (Used the 12 week McMillan Strava plan, and bombed after 20 miles. Goal was 3:30)
PB: Dublin 2016: 3:21:45 (Used 18 week P+D up to 55 plan, almost even splits, tough last 2 miles. Goal 3:22 )