I do not think that the number of individuals testing would have any bearing on the difficulty of the NPTE exam. Also, because of the secrecy of the questions and way that fsbpt weights scores, nobody could really know that answer without taking both exams and even then, it's really more subjective.
That being said, if you graduate before the end of May, you should be able to test in July. I would get on top of the paperwork now though and check state/fsbpt deadlines to register because it typically takes several weeks for them to process all of the paperwork. From my experience, it is best to start sending in what you can (as far as apps and fees) as early as you can, knowing that it may take your school a little longer to send in their part.
