We arrive at Terminal 5, our friends arrive at Terminal 2. We had planned on taking a taxi together to our hotel in Stockholm as we arrive about 20 minutes apart. How easy is it to get between the two terminals?
Any reason for taking a taxi instead of the far more convenient, faster and likely cheaper Alranda Express? That would probably be the easiest way to meet up if arriving from separate terminals.
I had to change flights once at Arlanda, and I don't recall any difficulty getting between terminals.
Arlanda is a small airport. It will be easy to meet up. (The terminal numbers make me think of Heathrow, not so, very misleading.) Check out the airport map and pick a meeting place, if you won't have phones working. Also, the Arlanda Express is only good if you can walk from the train station to the hotel. Otherwise, it is less expensive to have an Airport Taxi take you to your hotel. There is an agreed price, last year it was $380 Krona. I learned this from my hotel, so you can always call the hotel for the way to arrange it.