@wilfredh in my human factors course in ~1989, the research we read all said cursor keys were #1 for efficiency when navigating text. #2 was trackballs. Mice were dead last. Of course Steve Jobs had to popularize mice...
Mice lose by a huge margin because they require you to pick up your hand and move (possibly multiple times) and then re-find your position on keyboard.
Trackballs also allow higher precision fine motion as well as coarse motion.