Just googling for some page that speaks of Taraka Brahma:
WALKING WITH MY MASTER - Taraka Brahma
The Coming of Taraka Brahma
Brahma Cakra: The Cycle of Creation
So, where Bahaullah seems to focus on prophets or divine manifestations and many Hindus focus on avatars, Sarkar stresses the recurrence of Taraka Brahma, who is however each time a unique personality but with similar qualities (that of a bhagavan, someone who controls all of the bhags or occult powers and has other specific qualities such as those of a mahakaula).
Both Shiva and Krishna were earlier advents of Taraka Brahma.
A quote from the third page I found:
"To attain moksa Shrii Shrii Anandamurti introduces a unique concept: Taraka Brahma. According to Ananda Marga philosophy, Brahma exists as the manifested universe (Saguna) and another infinite portion of Brahma remains beyond the influence of the operative principle and is undifferentiated (Nirguna). The link between the manifested and unmanifested Brahma is Taraka Brahma which means Brahma the liberator. If a tangent is drawn touching the ellipse which we use to represent Saguna Brahma, the tangential point is a point which is both inside and outside the ellipse.
This point is Saguna and at the same time is also Nirguna. This point is Taraka Brahma.
The great spiritual teachers who appear from time to time in human history are embodiments of this tangential entity whose role is to guide individuals to complete self-realization and ultimate union with Nirguna Brahma. The concept of Taraka Brahma is a devotional concept and explains the reverence which is given to great spiritual masters."
I would never say that the theory of Bahaullah is wrong. But after learning about the many qualities of Taraka Brahma in Sarkar's books about Lord Shiva and Lord Krishna, my focus is on this frame more than on other frames.