craig, i see you arent using the "tow" pin to move the load
but id like to weigh in too lol
many ppl misunderstand what the pin is for due to its name (or what some perceive its name to be)
tow actually implies moving of the machine on a flatbed tow truck
i prefer to call them recovery pins so towing isnt implied

forklifts are never designed to tow a load (as your manuals should say kids ;] )
think about it
if you add a load to the rear of the machine what happens to the center of gravity?
where would the rear fulcrum be? the steer axle
most of the counterweight is behind the centerline of the steer axle making for some very dangerous physics

aside from that

the term "material handling" is a broad term used for our entire industry, which includes much more than just forklifts
if you have material and it needs to be handled, in one form or another, then we're the industry you call

tugs pallet jacks even automated pickers all fall under "material handling"

a "forklift's" true technical name is an "industrial lift truck"
lifting is implied in its description

to move these tubs you would have to apply some lifting pressure to overcome the friction of the ground, however minimal, and obstacles (garbage, broken pallet pieces, etc)

the load center and overall weight are WAY out of range
i would see an issue

i think electric pallet jacks (rider) rated for 8000lbs (toyota makes them) could handle the load safer
or even a tug
maybe they can talk to toyota about modifying something to handle your unique "material handling" issue

a forklift probably isnt the best solution

and like ed said how do you lock the load to the machine so it doesnt slip off when reversing or braking while traveling fwd ?