>>12874396OP, just to make sure, you do realize that not all the volumes are translated in English right? Viz Media is going all over the place after the GSC arc. They've essentially skipped FRLG and Emerald altogether (vol. 23-29) and is already translating RS, DP, HGSS, and BW (vol. 15-22 for RS; 30 onwards for everything else) all at the same time despite being influenced and referencing previous volumes.
Basically, if you order these, know that some volumes have been skipped after the GSC arc. If you don't know the order it's:
RBGY--->GSC--->RS--->FRLG--->Emerald--->DP--->Platinum--->HGSS--->BW
FRLG and Emerald were never translated. Everything else is done or undergoing English translation currently by Viz. Online translations for the missing chapters can be found online. And yes, you'll need to read the missing volumes, otherwise you'll be confused when future chapters start referencing back to them (HGSS has tons).
Hope this explanation helps, anon.