Well, I see nothing wrong with that set up, except the length. I wouldn't try that, but there is a haulage contractor who works for our JCB dealers here, and they use interlink combinations to transport three 3CX's, one on the interlink, the other two on the actual lowbed trailer. they also transport Massey Ferguson tractors, maybe four or five little ones at a go. Just that that is a very long interlink!
And on those YouTubes, I like that "toys" of the harvestor. Very cute. And after paying close attention, You see that those are not full lowbed trailers they're using. They look very small for those combines, though, and then they put a grain pup behind it.