Weight advantage trumps horsepower.
Those farming innovations made industrial-scale farming possible and led to the 95% reduction of labor needed to feed the world. Of course, that led to obesity, heart disease and death, but it's much better to die well-nourished at 75 than under-nourished at 45.
Not as much as one might think. Power is the product of torque and speed. Note that the diesel gets smoked every time he tries to move from a standing start (Speed = Zero!) Ie no power. A steam engine develops maximum torque at zero RPM and thus has the advantage over the combustion engine from the get-go every time.
The "engineer" driving the steamer knew his equipment and how to maximize its strengths. The diesel jockey didn't stand a chance.
Regards,
GtG
Gearing is also key. That is a small JD with high gear ratio. Hook that steamer up to a big, 400 hp JD field tractor in low gear, and see the roles reversed with less than half the HP.