Replace Object(s)

How about an effect that would replace selected objects with object(s) from
another layer.

This is the way I envision it working:

1) Place any given number of objects into the top layer which would be
empty otherwise.

2) On your working layer, select the objects that you want to be replaced.

3) Run this effect, which would give you options for how you want the
replacement object to be placed. You would set the insertion point to
match for the original and replacement objects (i.e. bottom left, top left,
center, etc), random transformations for replacements upon insertion (i.e.
scale, rotation, x/y offset), and whether to cycle through the replacement
objects for each original object or to randomly select a replacement object
for each original object.

Any thoughts about the feasibility of something like this? Would screen
mock-ups be useful to better explain what I am suggesting?