What I've been known to do is
1)Spray the symbol instances
2) Expand (just the object)
4) Go to Object > Transform > Transform Each, select Random, set a maximum Scale percentage value (in this case, less than 100%) and maximum Move values.
5) Click OK, then press cmd/ctrl+D a few times.
It's possible to change values, higher or lower, as often as you like. And it only takes seconds to start over and try larger or smaller symbol instances to start with.