If the purpose of acquiring a tiller is plowing “under the beam, a carrot,” then a small petrol tiller will suffice. If you need to take a "workhorse", then undoubtedly the choice falls on the diesel walking tractor (preferably a heavy diesel walking tractor).
Now consider the financial side of the issue. If you can purchase European copies - it remains only to be happy for you. If the budget is limited, then I advise you to look at the Chinese models (for example, the cross-over). With proper care of equipment and timely monitoring of technical fluids of the motor-block, it will serve you no less than its European brother.
Diesel walker is characterized by high tensile strength, power, reliability and long service life (in relation to gasoline). Competently chosen walker can perform a huge range of chores (plow, mow, pump water, clear snow, carry cargo). It will be a good alternative to a mini tractor.