I would love to see what the actual questions that were put to the stormers players - if it's along the usual lines of "who do you think are going to be your toughest challenge" etc, then how is it arrogant to name a couple of sides that aren't Australian ... just because they don't see them as the greatest threat, doesn't mean they aren't a threat.
If you are playing each team in your local franchise twice, and the teams from the other franchises (and not all of them) only once, the strongest teams in your local franchise are going to provide the greatest threat to your chances aren't they?
Looking through the schedule, the only games the Stormers play outside of South Africa are against the Blues and the Chiefs ... what's harder? a home or an away game - i'd be more confident of a home win against the Reds than an away win against the Blues.
Also, i'm not saying the Reds, Waratahs, Brumbies etc, aren't good teams, but it's been a while since any Australian team has gone all the way and won the title, so of course they're going to say the Bulls, Crusaders etc.