Hi @dilesj,
I took PA, PPD, & PDD in that order. That made sense to me because it’s the order NCARB put them in and it follows the order of project development with PA covering topics related to schematic design, PPD covering topics related largely to design development, and PDD covering topics largely related to the construction documents phase.
But, the order you take the exams is in largely personal and it’s up to you! Do what plays to your strengths! Go into the exams planning to pass!
One thing I would definitely recommend is studying for PPD & PDD together. Those two exams in particular have a lot of overlap. In an ideal world, I would allocate 1 month to studying for both PPD & PDD together. Then 1 month focused only on PPD before taking the PPD exam. Then spend 1 month focused only on PDD before taking the PDD exam.
My personal experience with PPD & PDD is that I failed them back to back. I was using Black Spectacles, but I didn’t hold myself accountable to my study schedule and admittedly did not try as hard as I should have. These were my last exams and I was not happy about failing. So, I dug into Black Spectacles lectures. In the span of a month I watched every single PPD lecture and filled up a notebook with notes & sketches. Then I took the PPD exam and passed! I followed the same process for PDD. Watched every single lecture in the span of a month, bought another notebook, filled it with notes, and then retested with positive results.
While I did not plan on studying for them together, the back to back failure gave me familiarity with both which I feel helped the second time I took them.
The order you take the exams in matters a lot less than making sure you give yourself enough time to study and don’t slack (like I did the first time around 
). Just go for it!
Hope this helps!
-Darion