At first that seems right. But there is a big BUT. Even Tesla has outsourced a lot of components. A lot of the components except the drivetrain is being outsourced. There are only 2 manufacturers for airbags in the world. There is only 1 good quality manufacturer in the world for the in car rearview mirror. There is only 1 manufacturer for the Homelink system with its best features developed by an Audi engineer I personally know. (All the Homelink systems in the premium cars are this only one system and I know the 2014 numbers sold to Tesla at that time.) The brake system in the Model X is from Bosch. And so on.
So Tesla is at the same level of outsourcing like every one else. So actually you can compare the numbers.