Driver licence category during conversion

Hello forum members,

I'm seeking guidance on converting my USA Class C driving license, which allows me to operate vehicles weighing up to 26,000 lbs (11,793.4 kg), to a Swiss license category. I have heard that someone from an EU country with a Class C license received a Swiss B121 license during the conversion process. Can anyone provide information on:

The likely Swiss license category for a Class C (26,000 lbs / 11,793.4 kg) license holder from the USA?

Is it possible to receive a B121 license during the conversion process, similar to the case of the person from the EU country?

Additionally, I would appreciate any details on any additional requirements, tests, or commonly requested documents or translations for license conversion in Switzerland.

Thank you for your help!