Spacing on foliage painter

Hi all.

When painting foliage (trees, especially), when having more than 1 foliage type active, I find that the different meshes clip into one another.

I know you can set the radius on individual meshes, but that doesnt seem to help for painting multiple meshes at a time.

It almost seems like there is ‘group meshes and apply radius to all in group’ option that would be useful here.

Can anyone please clarify / assist?