I’ve been in the farm fencing business for the better part of 20yrs and usually work by myself. I’ve tried many different post drivers, both tractor and skid steer mounted, and most have major downfalls when trying to work by yourself. The units like the Danuser hammer with the grapple option do work with only the operator, but good luck ever getting a post straight and plumb without a helper to check it as you are driving. Same with the vibrating type, works superb with two people. Maybe straight and plumb don’t matter in the areas you are working IDK. I build a lot of board fence for customers so it has to look good.
My current one man fence building rig is very simple and low tech, just a Shaver HD10 post driver on a Kubota L2501 tractor. I set it up last fall and I’m still refining it but I’ve driven several hundred posts with it and am very pleased. The tractor doesn’t have a loader on it but instead a custom front bumper that can be used for pushing posts to straighten, also has a chain box, receiver and tie down ring. The tractor is easy to get on and off of and the visibility to the bottom of the post driver is very good. I disabled the seat switch so I can operate the HST pedal from the ground standing along side the tractor for minute adjustments. Actually I can operate all the controls I need from the ground, 3pt, HST, steering wheel and parking brake. The driver is plumbed into a power beyond loop so its always live. I usually pair this rig up with my SVL 65 on larger jobs, both fit easily on my 25’ pintle hitch trailer. May not be what you’re looking for, but its the best solution I’ve come up with so far for a one man fencing rig that doesn’t cost $100k+.