It don't think it says they both have to be next to be the same savage province. You could have one next to Ghulistan and one next to Pictish Wilderness. Furthermore you can get next to Tundra in two provinces, even though it is not in play. As I read it that would also count.
I can't check the actual card though because we have a game in progress and its somewhere in the pile.
Oh yeah, you could march all the way across the board and get one next to both. Didn't think of that. It seems like it would be difficult though.
But I also think you're right that getting them next to Tundra should count too. That makes it easier. It gives Turan a big advantage in getting it done but they have an advantage at the start for that objective even with more players since their kingdom starts the closest to two different savage provinces anyway.