Sounds nice, I like this theory, but... Reshiram/Zekrom recognized N as the hero and the counterpart recognized a human (the player), so it's implied they're in a way the same. So, there's no way N could be a Pokémon himself.
Besides, there is the fact N used a Zoroark in his final battle in BW1. Actually, I think it's the same Zoroark he used, the one that appears in Victory Road (and inside Old Plasma's house when you use Memory Link).
Also, The Zoroark in Lostlorn Forest in BW1 and BW2 are different. From BW1 is implied Zorua/Zoroark keeps its gender when disguised as a human (the kid-Zorua in Castelia is always male, the woman-Zoroark in Lostlorn Forest is always female). The Backpacker-Zoroark that gives you TM95 is male, so I guess that's a male Zoroark.
Though, I agree there could be a complete.... tribe? herd? of Zorua/Zoroark hidden in Lostlorn Forest.