I keep the heavy stuff on the bottom of my tool cabinet,
for one reason; to keep it resistant to tipping over.
I was surprised one day when I had about 3 drawers open at
once, that the cabinet started to come up off the 2 back wheels!!!
Since then, I keep the body dollys and such in the bottom drawer,
working up to the hand wrenches in the flat top drawer, to give
a lower center of gravity....