Evolutionary Distance is the difference in evolutionary levels. Evolutionary levels can only be measured if evolutionary progress is assumed, so the determination of evolutionary distance requires measurement of evolutionary progress.
Controversy
By contrast, many evolutionary biologists who deny progress measure evolutionary distance only by the extend of DNA changes that can be measured statistically. However many evolutionary rules outlined here on these pages cannot be applied without accepting evolutionary progress.
The rule of dwindling influence with increasing evolutionary distance belongs to those rules.