That is good information; I followed it last year when I rebuilt my turbo. I did not have to worry about balancing because I did not replace any center pieces. I also made sure that I indexed the impeller to the nut. Torque everything to specifications, line up index marks, and you should have no problems.
My turbo had a nut securing the compressor fan to the shaft. I beleive his documentation points out specifics about balancing.