Hello Fei Hua,
Yes, I understand what you mean, and I think this feature makes sense.
At the moment, each Path usually needs its own Distributor, so if you want several different child states on the same level, you have to create several Distributors. As you mentioned, this can make it difficult to keep the same density, angle distribution, and avoid overlaps.
Instead of adding a separate "Random node" (as you show on your screenshot), I think it may be better to add a new mode to the Switch node. In this mode, one Distributor could be shared between several child Paths, and the Switch node would decide which Path should be used for each distributed item.
With the Switch node, you could also use a Random node to make the switching between Paths random.
This would make it possible to use one Distributor density value for all these child Paths, while still allowing different states, for example branches with many leaves, fewer leaves, or no leaves.
I'll add this to my TODO list and try to implement this feature in one of the upcoming updates.
Thank you for the detailed explanation and examples!