Better scheduling among hosts

I have 2 hosts and I am using cattle. Both hosts are almost the same. Same RAM, same number of cores, different CPUs, different SSD size.

I created 4 services with 2 containers each. I expected Rancher to be smart enough to at least have the same amount of containers per host.

But at this moment it runs 6 containers on host1, and 2 containers on host2. And I think I’ve seen it run 7-1 too.

What logic does it use to deploy containers? Why it didn’t decide to run 4-4 containers between the 2 hosts?