They may be from somewhat different dates. One burned down by accident (or not by...) and was replaced by one that burned down later. Or, they needed more space.
How boring your explanations are!
I like the idea of competing halls, with Viking cheerleaders urging on their troops with lusty cheers like:
“Ve’re from Oslo, as if you didn’t know it! Ve’ll kick your rural ass if you dare to show it!”
with the response:
“Trondheim, Narvik, Hammerfest and Bodo!
Run all over those fairies from Oslo!”