cownd, those are no longer "tow pins" those are now "transport tie-down points". (big plaid button up shirt red-neck grin)
What it matters is how safe can you stop and/or steer a series of trailers vs how safe you can stop and/or steer a forklift that has picked up and is carrying a properly loaded pallet or '****' of materials around pedestrians, and just where the brakes are mounted to (it may not be the best idea to have the only brakes on the very front wheels of a train).
AND
if I was designing a warehouse that was going to use a "train", these days, I would sure be considering AGV's... wages are a continuing expense, AGVs are too, but not near as many wages per ton moved/hour operation 24/7