Multiple Surface Generator Density Maps



I am trying to scatter multiple objects (two groups with objects) randomly on a ground mesh with Surface Generators and Surface Gernerator Density Maps, but it does not work. It only takes the top Surface Generator Density Map on them both, does this even work?

I have tried to use Weight Maps to drive the Surface Generator, but Modo 11 is so slow, so had no luck finishing the maps… Why is it so slow? My system is like at 10% of its power (55GB Ram free, CPU at 1% load).

Update: Got it to work with Weight Map, but is this truly the best way of replicating multiple objects on a surface?

64 GB DDR4 2400MHz
m2 SSD Samsung Pro with 300+ GB free diskspace.

Starting to regreat my Modo choice…