There are how many different tribes? Cherokee, Blackfoot, Ute...there are hundreds and all are different.
In China some even had their own writing. There is a program that comes on TV every now and then about 'nu-shu' writing. It is a totally different form of Chinese writing.
It was barely preserved because the cultural revolution burned everything they could find written in that language.
Also don't forget, those 'jian-ti' characters were created by the Communists.
The CCP went on a tirade to destroy all minority cultures. To them there was going to be 'one-China' and that meant everything. During the Cultural Revolution they destroyed so much of the various Chinese heritages.
For many years "Chinese/China" were used as synonyms for "Communism". If you did not believe in Communism then you were not "Chinese".