I actually think the included Hydreigon is the good one. Depending on whether you want to battle with it or use as support of course (for support, the other Hydreigon is obviously much better thanks to its ability).
I HATE cards whose only attack (or only viable attack, like Emboar's pitful "50 damage for 3 energy" attack or Magmortar's "Discard cards from your deck and pray you discard enough energies" attacks are useless) makes them discard a crapload of energies, crippling them against the next card to battle (especially in Hydreigon's case as besides the single-use Dark Patch, there's no energy acceleration). Hydreigon can of course grab energies from others, but then you cripple your entire team. And you can of course save it for last, but I prefer something that's always useful.
This Hydreigon has no such disadvantage, even has a 50/50 chance of negating an opponent's turn of energy attachment (forcing a re-attachment. Or your opponent gives up on his Active and saves you alot of damage) slowing down your opponent, and against weaker Pokemon it can even nicely heal itself to prepare for tougher battles.
Of course, no such thing can be said about Garchomp. The other Garchomp has an amazing energy-for-damage ratio, its first attack even lets you discard a Special energy card with 100% success rate, and while its second attack has a disadvantage, this disadvantage is so incredibly small it should not matter except against Durant.
And indeed, it's really weird they use the other Garchomp and Hydreigon and decorate the entire product with. When it became known it got the "bad" ones, I actually thought it might perhaps have both versions (x1). But since the decklists are known, that's disproven.