This tool uses Geometry Nodes to instantiate geometry from 5 different collections at the same time and allows you to quickly look dev complex scenes. This tool comes with an auto height and normal mask filter, so you don't need to waste time painting in most cases to get a natural result. It also allows you to reduce the amount of instances on the viewport, so the scene don't get too heavy when you working on it while keep an insane amount of instances for the render time.
 It has a gravity control so the instances are oriented in a very natural way. Even it letting you to use 5 collection you still have full control over each collection independently.
 To use that you just need to Append the "MultiScatter Tool.blend' to your scene while selecting it inside the NodeTree folder, add a Geometry node modifier to your mesh and select the MultiScattering Tool, change the Density and add your geometry collections to the inputs.
The is also a single scatter node called "Scatter", that has the same features but allows yout to work with a single collection.