Hi @wickene ,
I talked about my own experience in studying for PPD & PDD in a post awhile back. This might help!
In an ideal world, I think I would study for both for a month. Then spend one month on PPD only and take it. Then spend one month on PDD only and take it. This has the advantage of giving you time to absorb the overlapping material and a chance to delay your 2nd exam if something goes wrong and you need to reevaluate your study schedule.
But that’s just my testing strategy. Personally, I don’t think I could handle two exams so close to each other. If you think taking them back to back will work for you I say go for it!
Good luck!
-Darion