I heavily doubt it'd change much. The fans of Rugby Challenge do seem to hate RWC with a passion. Whereas many RWC/RC fans seem to be keenly interested in both.

I play my mates off-line a lot. I hate having games between two of us decided by a random ball flying out the back from a half-back pass and line-outs that are extremely unwieldy and without a decent maul option, so on a gameplay front I prefer Rugby World Cup just now.

Both games have got a hell of a lot of potential, I really think if each had some added input from the long-term fans then they could both be a lot better. I'd give neither game a score over 7 the way they are and both succeed and fail in totally different ways.