It's nothing to do with crowds but the toss. Let's face it, win the toss, win the match. This second test, although the wickets aren't the same, is a mirror image of the first test. Probably the only fair method would be to take it in turn to have the choice of batting or bowling. If it's a series of an odd number of games just have the toss for the final game. The toss is influencing results too much.