>>19349898Not unless you count the new version exclusives in X/Y: Spritzee, Swirlix, Skrelp, Clauncher, Xerneas, and Yveltal
The reason for this is: (excluding events)
Every Gen1-3 Pokémon is catchable in at least one Gen3 game and also at least one Gen4 or Gen5 game (even without using Pokewalker, Grotto, or Dream World).
Platinum lacks Glameow, Stunky, and Cranidos or Shieldon, but all fossils are obtainable in Gen5/6 and Stunky is in Kalos.
The only Unova-dex version exclusives from B/W that aren't also in B2/W2 are Tornadus and Thundurus, but they're available in Dream Radar.
Matching up all the version exclusives to minimize the number of games you'd have to play is still fairly complicated.
In Gen3, you could complete the National Dex with only Emerald, Leafgreen, Colosseum, and XD. All the R/S/FR exclusives can be found in Orre. Leafgreen in particular was needed for Slowpoke.