As a simple test of independence, I calculated correlations between the normalized RCFR, RRF9R, DP/E, and DPdg.
These correlations also confirm that DP/E reinforces the measure of sure-handedness, but it is not a carbon copy of RCFR and exhibits virtually no relationship with range.
In summary, this statistical analysis provides some encouragement for including all four measures in the calculations and rankings that follow, giving priority to RCFR and RRF9R as the dominant measures of fielding.
Range-Biased Score = 60% RCFR + 30% RRF9R + 5% DP/E + 5% DPd9
Sure-Handedness (SH)-Biased Score = 60% RRF9R + 30% RCFR + 5% DP/E + 5% DPd9,