You want to put a hitch hauler on, AND tow a trailer behind it?? Sounds like a bad idea. My hitch rack moves a lot since the reciever and the insert have a small amount of slop. Think about how much a trailer sways on the hwy, then add another inch or two of free movement and you have the potential for serious problems. Ans the statement about tongue weight is not applicable for this, since the weight is intended to be measured at the intended hitch length. Add 2 feet, and that 100Lbs tongue weight the trailer has will be putting a lot more force on the reciever due to leverage. Don't forget to add the weight of the actual hitch rack, too.
So let's say you're like me, and you have a rack (custom made and very strong ) with a bike rail. I carry my dirt bike or a ski on it. I thought about towing a trailer, and the rack was built with the capacity to recieve a class 2 ball mount. I have a 4x8 utility trailer for my wife's atv. So I thought that MAYBE there was a way to carry both. So, I mounted the whole setup on the jeep, with no load and towed it around the block. It seemed ok, so I towed it on a 7 mile trip to pick up my toolbox. With a fairly small load it did seem to move a lot. I will probably use this setup for around town use at low speeds, but not for any trips.