When scattering more than one object, using geometry nodes, a collection info node can be used. The only issue then is how do you control the density of the objects being scattered?
A solution I came up on on stack exchange, provided an answer.
The user created a makeshift array using a domain info node, that calculates the numbers of objects in the layer. He then used a mesh line node, along with index nodes, to create attributes, for isolating the object in the collection, and allocating a density to it.
Though not the most elegant solution, it actually works really well. All you do is duplicate the index density node for each object in the collection.
The solution is here , if you want look at it on stack exchange. If you prefer to watch me create the solution, in video format, please see above: