Sorry, I don't like the look of that hitch. Like Brian said, it is extending the load too far away from the support.
The deflection increases exponentially with the cube of the distance from the support, but the stress increases linearly.
One of my concerns is that the ball will not stay tight. The flange isn't supported front to rear & that is the direction of pushing & pulling. This will result in it working loose. I've had properly supported balls work loose. Is there a support sleeve welded inside the tube? If not, the tube walls will bend under load & the ball will become loose.
I'm not a fan of welding trailer balls on either.
Then there is the vertical loading. In ANY ball coupled hitch, there will be 2 kinds of vertical loading, one is from expected loading & is easy to plan for, the other is a result of the unexpected which is much more difficult to plan for.
Many assume there is minimal to no vertical loading if you are towing a car 4 down, however this assumption can be very wrong. If the rear raises during a hard stop, the tow bar is no longer horizontal. If the toad is pushing, this angle will get worse as the toad's front end drops. This angle will create a vertical load on the hitch.
For example - assume a tow bar is 3 feet long (ball to toad's bumper pivot) & the coach rises 6" & the car dives 6" (a height difference of 12").
If the toad is pushing 2500# in the horizontal plane, the resultant is ~884# in the vertical plane.
If the height difference is 16", the same 2500# push will result in a 1240# vertical lift on the hitch.
(These are only example numbers to show how a little angle can go a long way to increase the actual tongue load. The force of the push can exceed the actual weight of the toad due to momentum.)
I never thought too much about this until I was riding beside Dad's coach & saw how much the tow bar moved when he hit the brakes hard - AND, he has a functioning brake buddy in the toad applying the brakes.
Another way to look at it, in theory, with a long enough lever, you can lift that end of the bus by yourself (of course this assumes favorable levers & fulcrums