Diversity of perspective is important, but not of opinion. You want to build strong opinions using many different perspectives. Random opinions are not interesting nor useful.

Should Google start hiring more flat Earthers too?

If they are good at their job, sure, why not? Ironically, I doubt anybody would have been fired had they argued that the Earth is flat.

Also, I'm not sure what you're getting at with the distinction between perspective and opinion. Regardless of whether you think Damore presented opinion or perspective, it surely wasn't random.

To reiterate my previous point: considering how things played out, it's obvious that the subclass that you called 'less powerful' is actually quite powerful.