The "trigger finger should have one job" argument has always seemed like a bit of a blunt instrument to me... a BAD lever sits 1" forward and 1/2" to the right of the trigger, extending out past the side of the receiver. As far as finger movement goes, that's not an insignificant distance. Most shooters have control of their trigger finger down to small factions of an inch (i.e., prepping a trigger). Safety and discipline are safety and discipline.
Guess now isnt the time to bring up a M1 Garand