Even if there was anything in terms of authority or jurisdiction, He shares it with so many other divinities to each of whom She has allotted responsibilities as well as the associated authority and wealth of Power. On the other hand, the ‘I-am-one-with-You’ people are one with Her and so they enjoy all Her aishvarya in fullness. So they are the greater ones!
I must warn you here. Let us not be carried away by this poetic devotional exaggeration. There is no separate identity for either of Ishvara and devI. In fact what is Hers is His and what is His is Hers.