I wouldn't put my fastest outfielder in right field, but the one with the best arm.
The Right-fielder does have a quick play option at 1st base on occasion and also has more chance of being challenged with extra bases. The old saying "hit behind the runner" applies. She will have equal challenge as LF on a sprint to 2nd base, more of a challenge on a runner to 3rd, and will also be challenged more on a tag up at 3rd than the left fielder would.
IMO, more speed in CF and better arm in RF.