I know someone who wants to do pedo and if not then GPR. But, is it possible to apply to both at the same time and see which one you get into? Go to all interviews...Rank all the pedo higher and the GPRs lower..something like that? How does that work?
I personally would focus on what you, or whoever you know, really want (pedo), if not getting in, to try post match GPR available positions, they usually have lots of spots each year and getting somewhere shouldn't be a problem. unless money isn't an issue for the interview related expenses and the emotional roller coaster that candidates go through interviewing, go for it...
But as far as a matching technicality of pedo and gpr goes, I believe that ranking from top to bottom as mentioned is the obvious way to go