We saw many a pick up towed 4 down behind MHs, As ( rear and front gas or diesels) and Cs ( again either fuel) both auto trans and manual. 4 WD trucks have a neutral in the selector switch to allow towing.
It. also allows carrying other cargo like a M/C. Your expectation of power,economy and gcvr is the limiting factor. Definitely install auxiliary brakes on the tow. You cannot have a heavy vehicle pushing the coach.
A consideration if you are adventurous in your travels that puts you in a situation is,
I have seen and done backing up a 4 down many times, just have a spotter watch the front wheels. Its no different than backing a trailer except for the front wheels, if you have to turn sharp they may not follow the turn. It is a myth that 4 down cannot be backed or that damage will happen. Hitches that can pull can also be pushed on.
Its MFGR Cover Butt Speak.