i dont think that the theory of pokemon that follow you in the game is the pokemon in your fist slot is confirmed (if it is that go ahead and lock this) what im proposing is what if the pokemon that follows you in game is the pokemon that you transfered to the pokewalker...it only makes sense, the pokemon is with you in game and out...tell me what you think

How could it be the Pokemon you transfer to the pokewalker? if I'm correct (and i could easily be wrong) you have to TRANSFER the Pokemon to the walker, meaning it can't be in both at the same time.

This has been confirmed long ago. The Pokemon that is in the lead position of your team will follow you, it doesn't matter if is a lowly Caterpie to the mighty Steelix.