I can’t speak for all bike parts, as to the same line or truly counterfeit. I have purchased bike parts off eBay that came from China and have not had issues.
Bike parts, while high quantity, might pale in profit compared to counterfeit frames or golf clubs. In those cases the devil is in the details. The cost to accurately reproduce a counterfeit down to the very fine details is what usually is the clue of a counterfeit item. And they will never weigh the same.
For pedals, I would think a close comparison with the real thing, would confirm if it were real or counterfeit. Any small detail, tab, rivet, finish, crispness of lettering. These operations probably need to produce a run, dump, and move on. I doubt they can duplicate the real item exactly.
John