From a software perspective it’s the same. The software doesn’t care if it is telling a servo to rotate or an ECU to increase speed. Both systems need an external speed sensor feeding in. The only extra on the mechanical engine is adding a generic servo.

Both systems can use an open bus protocol. The mechanical system resists proprietary rent seeking as an added bonus.

We’re commenting on an article about farmers willing to pay for tractors with rebuilt all mechanical engines when the exact same tractor could be built with a new computer controlled one. That choice was intentional.