I'm afraid I don't know. I don't have the games and I haven't even gotten the ambition to RNG Arceus in B/W yet. For what I hear the process is the same, only the PIDRNG isn't reseeded when you warp to the entralink. Instead, the PIDRNG is advanced a few frames and then stops (unless you advance it via chatot or NPCs). It should be the exact same process just a lot easier to control the PID, but I'm not sure of the exact details beyond that :/ sorry