Good point Tommy!
I was so impressed with the A-frames when I was a digger, that I made my own to tow a Morris Minor ute that I had bought from a cocky and I used chains. I found out rapidly, that if chains are used instead of rigid pins, the towed vehicle wanders all over the place and therefore cannot follow the towing vehicle exactly.
So my great idea wasn't so good, but at least the brake-less Morrie didn't run into the towing car,
Cheers Charlie