well, i think i have the motion designer approach working.
i originally thought i could use a particle emitter to generate the gumballs (fx_linker), but getting them to keep from going through each other wasn't working. then i realized i would have to select each gumball individually and activate it in motion designer one by one. (not fun!)
so, instead i just arrayed a bunch of gumballs all on one layer getting them as close together as i could within the glass globe and in layout let motion designer (with a little help from gravity) put the gumballs on top of each other.
here's a pic of a test i did...
i'll post an updated pic of the gumball machine soon hopefully.
hmmm... i wonder what motion designer would do with two objects (gumballs) that started out intersecting... more tests!