How to control the density of the weaver bird mesh?

Hey guys,

i have a mesh created out of 3 boxes. Those boxes should get a "exoskeleton" created with weaverbird. Now i would control this mesh a little bit more (less density, more irregular) maybe with attractor points?

My other thought was to create the exoskeleton with a voronoi mesh. Is it possible to place the voronoi Mesh just as shell? I tried it with the voronoi³ but i could not figure out how i use it just as shell.