Pokémon Black & White (be warned: spoilers)

[Maxpphire]

The way that Pinsir and Scyther are counterparts:
-They are generally found in the same area/the same way as one another (the only game with any difference at all is Platinum.)
-They are sometimes version Exclusives of eachother (Only with Diamond/Pearl, Fire Red/Leaf Green, and Red/Blue)
-Their base stats are closer then with Heracross and Pinsir
-They don't have to have the same moveset, See Butterfree and Beedrill.
-They have been counterparts since Generation 1. That doesn't change with any other pokemon that has a counterpart either.

The way that Pinsir and Heracross are counterparts:
-This Card

I would go with Scyther and Pinsir because there are more reasons.