I just refreshed my memory from the IBM Physical Planning manual. They never asked for more than a #8 and that was to bond an acre or more of non-stringer raised floor.
Usually a #12 was all they wanted
It was also in the bad old days when we were the worst EMI offender with the 400 amp switching power supplies and phase controlled regulators in our big machines. They were very crudely chopping up utility power with largely unfiltered power supplies. Switching transients were everywhere.
I am not sure who the "IT guy" is but he is sadly misinformed
