When draft animals are not available, these type of devices could be pulled with a cable. Perhaps using a hand powered winch, or pedal power. Or any ATV, car, etc can provide the power, if cables and pulleys give it a place to drive.
I think it might be practical to build a simpler (though perhaps heavier) all in one cultivator using off the shelf parts. Such a device could be assembled on vacation and given to villagers in a poor country for beta testing. The material that enables strong machines to be built by a novice is telescoping steel tubing.
For small farmers and the third world this type of animal drawn implement exisst for a long time. Jean Nolle has develloped many of them. Many today small French farmers use them in the market garden. One of the suppliers is www.Prommata.org. Many of the French users work with small donkeys. But I love the idea of building these implements by the farmer themselves. If one needs more information, please contact me.
If you are rich, you feed a horse,
but being poor you work with an ox.
Make yourself as serene as a flower, as a tree. And on wednesdays, as serene as this tiny ad: