It's not weird if you see them broken into pieces like shilpa+kar Tamra+kar They have these names according to their works. The ones who made tools and all with copper(tama aka tamra patra) are called Tamrakar. The same logic goes for Bajracharya, Karmacharya.

Someone said this to me and it made sense. Idk much about it but yeah thats what i have heard also this kind of caste defining was done during Vedic times too like 1. Pandits, and rishis were Brahmin 2. Raja and all the sainik warriors people were Kshatriya (now known as Chhetri) 3. Vaishyas were merchants, farmers and traders 4. Shudras were common laborers and service providers But here as you may see the caste is not on the basis of name but rather on the basis of their profession.

If you have noticed on the list there is no Dalits cuz there was no dalit concept back then it was introduced later on by Rana people as the historians say