Needing to cut 150 people suggests catastrophic mismanagement. I get that workloads change, orgs pivot, business has to do business shit, but if you've missed your headcount requirement for whatever work you needed to do by a HUNDRED AND FIFTY PEOPLE!? What even.

Management and leadership is practically a lost art these days, so many organizations are just filled with managers who haven't the first fucking idea how to actually manage people.

All that said to be like: "Well how SHOULD we correctly fire 150 people?" I dunno, to me that's like saying how do I hit a tree with my car in such a way as to make sure I'm not paralyzed? Like so much has already gone wrong to bring you to where this is a pertinent question that I don't think there's really a right answer at this point, there's just gradations of bad.