Comment 4 for bug 1697543

So if you have a sufficient number of replicas to move you can have 100 dispersion even after moving the maximum whole replicanth

If you go from 6 replicanths in z1 and 1 in z2 to 5 replicanths in z1 and 2 in z2 the dispersion metric should probably represent some kind of improvement - but I'm not sure how exactly... and we'd still need to related change.