I am not very clear in some aspects of the theology. In Jagannath deities Subhadra represents hladini or joy part of the krsna's internal potency. But isn't that position assigned to Radharani. Somewhere prabhupada has mentioned that subhadra is only 1 of 16 expansions of yogamaya. Is yogamaya sadasiva's consort?
sandhini is presided by balarama, can balarama be regarded as krsna's expansion as well as his energy?
And the other thing which GM mentioned in class once was sadasiva coming from one side of krsna and radharani from other side.
So I would request somebody to correct me and clarify the points which are hazy to me.
I'll give you a preliminary answer, while waiting for a more technical one.
Govinda is the Adi Purusa, and Radharanai is the Adi Sakti, so in a very broad sense it is said that all the devas and their consorts are ultimately expansions of Radha and Krsna. However, Siva and Durga are even more so, as they are the same as Visnu and his internal sakti, yet different. Sri Brahma-samhita says like milk and yogurt: "Sem sem, but dipharant"
Visnu is said to never consort with material nature, or Maya. As soon as he even so much as looks at Maya (to impregnate her with jivas), that is not Visnu anymore, but Sadasiva, the glance of Visnu.
There is a transversal relationship between Radha-Krsna and Siva-Sakti. You could say that Maya, maha-maya, is an expansion of Radharani, or in other words "yoga-maya gone yogurt". However, you could also say that she is the sakti of Siva, and that's also correct.
Siva's internal sakti is Krsna's external sakti. The fact that Visnu never "consorts" with Maya is expressed by the fact that she appears as Krsna's sister. Maya is interestingly also called Narayani and Vaisnavi.
I do realize, though, that all this doesn't answer you question. Yoga-maya and maha-maya can be two faces of the same coin, and in one sense the same, but why do they say expressly that Subhadra is yoga-maya?
I guess I can't help you after all.
As far as Balaram, he is quite a purusa. The fact that he presides over sandhini sakti doesn't mean he is sakti, as much as Krsna is not sakti fro presiding over samvit, or Radharani is not a purusa for presiding over hladini.
He is, however, quite interesting: God the servitor. I've always been intrigued by his position, how he IS the dhama (=service), which can be said of Radha as well, and how Sri Guru can be seen as a representation of either.
one more point I talked about sadasiva who is visnu tattva not about his rudra manifestations.