I am a Chinese person and I have never heard of mixing rice, or even owning more than one kind of rice in your house. It seems so foreign to me. Chinese households will have a big tub filled with rice, and it Is just “rice”. We buy it in 20-pound sacks.
It’s really interesting that the notion of different types of rice is mainly heard of in the cultures where it is not part of every meal. Guess they just imported it from everywhere and then decided to give them names.
There once even was a racist German rice commercial that made fun of “Master Fong” (or some other Chinese name) because he couldn’t eat the non-clumpy German rice with his chopstick. As a kid who loved Chinese food (or what passes as Chinese in Germany) I found that to be preposterous and instructed my mom to never buy that rice.