@1UZ-FE mentioned creating an object which could link two hitches together. I thought it was a good idea, so initially I went with the most basic route since it was also the fastest: I created a female hitch which could be installed on a pickup or roamer. That allowed a pickup to couple directly with another pickup & etc.
After grabbing that low-hanging fruit I hacked...
'Giant Chain' for coupling two vehicles together

'Giant Chain' for coupling two vehicles together