It's a lot harder to just throw a random woman or pee-oh-cee into that position on the basis of their genitalia/skin colour than it is for the minister's position. You can appoint anyone you want as minister. The only qualification you need for a minister's position is a pulse.

To become CDS however, you need to climb a very long, very difficult to ascend ladder. Like for an Army officer for example, before being CDS you have to have been the Army Commander. But to be Army commander you have to have done a stint as a division commander. To be a division commander you have to have been a brigade commander. To be a brigade commander you to have been a combat arms battalion commander and so forth all the way down to the Lieutenant/platoon commander starting point. And every single one of those rungs is highly selective/competitive, likely in a trade that's physically gruelling and involves a lot of field time. Most people vying for the next rung in the ladder get cut, and this happens at every promotion level. So to get even a third of the way to CDS takes an exceptional level of skill and competence.

So even if they just start waving the diversity hires past all the rungs in the ladder, it'll still be a generation before they're able to weasel their up to the CDS level. Hopefully sanity will have been restored and affirmative action will have been thrown in the dust bin of history before that happens.