Brahma is the Power of the Divine that stands behind formation and creation.
The dynamic aspect of the Divine is the Supreme Brahman, not the Gods. The Gods are Personalities and Powers of the dynamic Divine. You speak as if the evolution were the sole creation; the creation or manifestation is very vast and contains many planes and worlds that existed before the evolution, all different in character and with different kinds of beings. The fact of being prior to the evolution does not make them undifferentiated. The world of the Asuras is prior to the evolution, so are the worlds of the mental, vital or subtle-physical Devas, but these beings are all different from each other.
It is not by your mind that you can hope to understand the Divine and its action, but by the growth of a true and divine consciousness within you. If the Divine were to unveil and reveal itself in all its glory, the mind might feel a Presence, but it would not understand its action or its nature. It is in the measure of your own realisation and by the birth and growth of that greater consciousness in yourself that you will see the Divine and understand its action even behind its terrestrial disguises.
A sealed identity within her woke;
She knew herself the Beloved of the Supreme:
These Gods and Goddesses were he and she:
The Mother was she of Beauty and Delight,
The Word in Brahma's vast creating clasp,
The World-Puissance on almighty Shiva's lap, —
The Master and Mother of all lives
Watching the worlds their twin regard had made,
And Krishna and Radha for ever entwined in bliss,
The Adorer and Adored self-lost and one.