Trivia - Racing tires are not uniform in diameter. They mark the circumference on them with grease pencil so you pick a matching pair for the rear.
I would estimate there are differences in street tires too. The temperature of the mold and the injected rubber cause this. The hotter the injected 'rubber' is, the smaller the tire it produces. It shrinks when it cools. So workshift changes and unheated/cooled factories produce inconsistencies.
If a tire loses 1/8" of tread, the circumference drops about 1%. But hot/cold weather and pressure can change that even more.
And the Weird Factor. Tread squirm and centripetal expansion. The faster the tire spins the larger the dia. BUT, the more torque that is applied, the smaller the effective diameter.
Rubber stretches. When torque is applied, the area behind the contact patch is stretched, and the area in front is compressed. Some folk think this is 'slip' but it's not. It happens even when you have slicks glued to the track with VHT.
So small differences in circumference on tires is expected.