Moderators, from the bottom of my heart, "thank you for not letting one person run roughshod over another". The original op's question. Should have seen us to to the 4H fair! Pulled a 20' flat bed gooseneck trailer with tack boxes, grooming chutes, fans and gates for cattle stalls. Behind the flatbed was a pickup trailer with a slide in truck camper, behind that was an old '60's type of camper! Was it legal? Nope, but did it for 8 years, 17 miles one way. When I was baling hay I would put the AC WD 45 on a tractor toter, hook the baler behind that, then hook two wagons together, then end with the rake. Made a pretty good train. Where there is a will, there is a way.
I have a neighbor that farms land all over the county...few acres here, few acres there...and he is almost always by himself. He pulls his (old) equipment around with his truck...so truck pulling tractor, pulling haybine, pulling rake, etc. (for example) I think he does it this way to keep from putting "road hours" on his old tractors, plus then he has his truck where he is working so he can go fetch parts when something breaks...kinda smart really...
How the weight is Balanced is much more important than how much weight you have (within Reason, of course) Ball coupled ( I HATE the term “Bumper Pull”, unless it actually IS hitched to a bumper mounted ball, there is a LOT of design and engineering that goes into a receiver hitch, especially a weight distributing hitch), anyhow, Ball Coupled trailers even in tandem behave very well when loaded PROPERLY. Proper Tongue Weight is very important for safe operation of Ball Coupled trailers. As I have already mentioned, I have pulled Ball Coupled trailers in tandem, and they behaved VERY WELL, I wish that Oregon and Washington States allowed Tandem Towing, I would Love to put either of the boats, or the utility trailer behind the 33’ travel trailer we currently have, it would make Vacation much easier Oh, and as far as backing them up, it is just a matter of PRACTICE, just like learning to back a single trailer, some can’t even manage That. If you want one of the Best Values in Entertainment, on the next Hot day, get yourself a Lawn chair, a Full Cooler and head to the local Boat Launch, hard to beat for the Price. Most of us know the challenge of backing a 4x8, backing tandems is similar, the longer the trailers, the better their backing manners, yep you do need more room, but the longer the trailer, the slower they react to steering input, so they are easier to keep up with I am JEALOUS of those of you who can Tandem Tow LEGALLY, I am endorsed, and can Legally pull 3 trailers Commercially, but even with that license, I can stihl, only pull one trailer legally behind the pick up Doug