It is not that the drive train differentiates the car. It is that the drive train constrains possible electric cars to be poor fits for the existing mass market. Which provides a market opportunity for manufacturers that focus on what is possible with the technology now, regardless of how well it fits in current Detroit marketing plans.
By the time electric is capable of being used for comparable cars at comparable prices for established lines of cars for established auto companies, they will be up against entrants in electric cars that have lower margins and more experience. When existing car manufacturers try to switch over they will wind up offering an inferior car at a worse price than the upstarts. This is a story that has played out many times in technology, and it never goes well for the established industry giants.
It doesn't matter if the competitors are delivering sports cars or glorified golf carts. What matters is that traditional auto companies with traditional dealer networks will be unable to compete head to head when they become competitive with the mass market.
Everyone knows about Tesla. Go look at https://www.fastcompany.com/40517240/the-biggest-electric-ve... for a company approaching the problem from the low end. There are a dozen more where BYD came from. And other markets where competitors are developing.
There are many niches around the world for electric vehicles. They are filled with companies who are salivating at the juicy pork chop that is the US car market. Technology does not, yet, allow them to compete head to head in Detroit's main product categories. But when they finally can, established automakers won't stand a chance.