I wouldn't say far more. As long as oil is in high demand, sure, 50% of their exports are shipping reliably. But Sweden's GDP is 30% larger, much more diversified, and will withstand the eventual contraction of petroleum based income. Take a look at their respective exports:
https://commons.wikimedia.org/wiki/File:Norway_Exports_Treem...
https://commons.wikimedia.org/wiki/File:Sweden_Export_Treema...