Cord. Excellent post. I would like to add on to what you have already posted with what is required here in Texas (and it does make sense). Loads have to be bound with a minimum of two chains and once every 10 feet in load length. The total load rating of your binders and chains must be 1-1/2 times the the total weight of the load. For vehicles, it has to be bound at all 4 corners and implements must also be bound.
I just purchased a 25' tandem dually GN (2-10k axles with breaks) and a 2005 John Deere 310G TLB. When binding a backhoe and/or loader, it is required that you bind at all four corners and also one chain over each bucket and one accross the stabilizer pads to ensure that they do not drop if there is any hydraulic failure. That is a total of 7 chains and binders.
And definitely / / - \ \ is the way to go. I attached a couple of pics. As you can see, I thought one chain accross the back 2 corners and one for the front 2 corners was OK. It is NOT OK. I will be purchasing a few more chains. They are all grade 70 3/8" transport chains which has a higher rating than grade 43 high test. The laws are hard to pin down so I spoke to some people who regularly transport ag equipment.
Also check your DOT for drivers license requirements and trailer vehicle inspection requirements. If it is tagged ag, then there are some exemptions depending on tow distance. Here in Texas, there are different commercial license requirements for more than 10K lbs, 26K lbs and also if you are carrying passengers or hazardous materials. Maximum load width is 8' 6" and maximum height is 14'.
Safe towing.