There used to be a Husquvana machine on two 18 inch sized hard rubber wheels that had a 150 or so cc Honda engine on it that was pedestrian controlled I think it had a 600 mm cutting swathe .
Being pedestrian controlled instead of being power driven at the wheels gave me the advantage of being able to rock it to & fro when taking out massive clumps of thick grass etc. & for scarifying the ground back to bare soil.
It was also good for getting right up the the boles of trees without running into the tree and taking off bark .
It had a 5 mm thick nylon grass whip that could also be fitted with a steel wire whip or various brush cutter blades.
When I had mine I used to to clear 1 & 1/2 acres of high scrub , Rose-bay willow herb ,brambles , small self seeded cherry saplings, sycamores & sally willow saplings etc..
I have a spinal injury and also a wrecked left shoulder joint yet it was so easy to use .