Foliage tool - Radius setting only affects individual meshes, not every mesh selected?

I have 5 different trees I want to instance across the level with the foliage tool, but when painting them they only account for other trees of their own type, so I end up with a group of the exact same 5 trees here, the exact 5 there… I want them to be evenly spaced and have the tool randomly select from my 5 meshes, not place them all perfectly together in groups like it is. How can I do this?

This would also apply if I had multiple rocks, bushes, etc. I need to be able to give them an overall radius, not per mesh.