Swarm Agents: Is it possible to get a more even distribution ?

I finally got Distributed rendering up and running. Basically it works like a charm. My only little problem is a very uneven distribution.
I have tested with various projects, smaller and larger. Well most of them architectural projects. So no giant game world. The distribution across the network is extremely uneven. See attached screenshot. Most agents finish shortly after Collection Photons is done. A handfull work a bit longer and one machine alone renders the biggest part. I wonder if there is way to make it a bit more even ? Are there some tweaks or parameters that may have an impact ? Also I´d like to know a bit more about the background, how the splitting to various agents happens. I guess it ´s not like Bucket rendering.

Activate the developer settings in every swarm agent (in the settings) and go to the new appearing register tab.
There you can set up the amount of cores which can be used.
I suppose this is the only possibility to change something distribution wise.