There have been different ways of accomplishing this over the years. Now, with Dynamo, I would use this simple two step process:

  1. Create a unique type for each Planting or Entourage element (as Height is a Type parameter)
  2. Randomize a list of values and write them into the Height parameter

It is super easy with Dynamo. Here is how you make the unique types (GUID from Bakery, Duplicate Type from Springs, SetType from Clockwork):

Then, just push the random values in, like this (the Set List node is in Bakery too):

My last attempt at this was here.