Yes! We are " The Weed Busters "! My family, my brother and sister in law visited my wife's father to help weeding in his garden.
The 2 circular saws are very effective to weed in a large area like his garden, which is about 300 square meter or 3000 square feet. They don't have any complicated mechanism but require maintenance. My brother in law, an electric specialist, has knowledge and experiences in dealing with engines and power transmission so he was so reliable that he changed their ignition plugs, some worn-out gears and fuel.
Why do we have to be so "heavily-armed"? You can see the answer when you see the photo of the garden of my wife's father. He used to grow various kinds of vegetables and to sell them to local shops with his wife. But His wife died 4 years ago. He is also paralyzed due to a stroke. His garden has been abandoned for years and has become like "a deep forest" as the photo shown below. All of those weeds were almost 2 or 3 feet in height and had rooted too deeply to pull them out manually.
Our team spent about 1 hour weeding a whole garden and at last we completed our mission!
Other weed busters, my wife and kids, contributed to making his Japanese-style garden more beautiful by weeding manually.