The KC46 is being fielded by the US and a few nations that the US traditionally use the same arms.
The A330 is fielded by the UK, a couple commonwealth nations and KSA
Total number built is in the 30s for both.
* https://www.thedrive.com/the-war-zone/29933/air-force-says-i...
* https://www.aerotime.aero/clement.charpentreau/24184-no-fix-...