You make a very good point regarding part time supervisors. The value they provide, as well as the things they're actually responsible for, is all over the place. Some provide negative net value. Some provide tremendous value. Some can barely perform the most simple tasks with a LOT of hand-holding. Some are on the same level as FT supervisors (using "FT supervisors" as an average...since there are definitely some iffy FT supervisors in the competence department).
The company could gain considerably, IMO, if we eliminated and replaced (as necessary) PT supervisors providing low (and especially negative) net values. Realistically, the company might also want to look into different pay grades for PT supervisors (and realistically, that probably includes a grade below out new minimum, as well as one or two above), and/or have the highly competent PT supervisors as "part time specialists".
Maybe how the company uses part time supervisors is something that the transformation team can address and actually improve? LOL.