GIPs compliance being firmwide

Can someone help clarify this for me? To my understanding, GIPs compliance is firmwide which means any specific strategy or division of the firm should not be excluded. But this question says otherwise. Can someone please help clarify this for me?

According to what I understand, a subsidiary can claim compliance even though the entire firm is not, if they have their independent investment strategy, personel, and decision making process.

But here they are saying that the entire firm is claiming compliance but the subsidiary. Is that acceptable?

If so, what does the “firmwide” compliance requirement really mean?