What you don't understand is that when I retired the guy who moved up in my place got the rate I was getting and the same all the way down the production line...
The guy that got hired at the bottom got the bottom man's rate...
The company didn't save a penny and someone got a job that they didn't have one before!
I do understand what you're suggesting and perhaps my comment was overly generalized.
Consider that things like defined pensions are rarely being offered these days, but for those that have that agreement in place, the employer just can't arbitrarily end it, but what they will do is refrain from offering that to any new employees. Those pension liabilities, particularly the unfunded ones represent a huge long term cost.
As per the example at your (former) work, it doesn't always translate in that manner.... By in large, there is more pressure to replace people at the upper end of the salary/wage scale than those lower down on the ladder for obvious reasons, but often overlooked are the payroll taxes the gubmint assesses which are a percentage of that employees salary.
in the end, the actual wage/salary is only one component of the related costs
