It's interesting on individuals thoughts on the paper exams, the only requirement I had was to do air law before first solo and then complete the remaining exams before the test.
One of the last exams I did was the Nav (not my favourite) and that was two months after doing my Qualifying Cross Country. After passing the GFT I then did my RT practical. I did the RT written the morning of my test (2nd attempt - dare I say).
I only failed air law and RT first time around.
I spent ages and ages studying for all the exams following my failure of the first exam. Granted most ended up close to the 100% and even now I feel happy doing them again and passing if necessary. When you have your licence you have to rely on what you have learn't and new experiences.
In hindsight, I wish I had done all the exams before started to learn to fly. Helps with the understanding along the way and your not tied to having to cram in at the last minute.
Good luck with the exams.
EX DGR