Chinese said they train OD first because JR gets its' elastic effect from OD. I don't know if I can believe that or not, but the guy said he got double pop on JR because of that (OD was 16 or so and JR was around 5-6).
I know my training regime will alwas be 1 on 1 first, then OD. And after that, JR and/or PA.