Blocks that are formed based on a shared vision but not agreed-upon mechanisms will certainly fail. The only thing BRICS countries agree on is the vision to change. It’s unclear what is the alternative vision. Clearly India for example will not support China/Russia’s vision of a global kingdom.
The acceptance of Iran also sends mixed signals. BRICS is meant to be the block of emerging economies while Iran’s economic performance (compared to similar countries) is very poor and there is no sign that it is moving away from Oil dependency and toward prosperity. BRICS is merely a vision, a vague vision. If India, for example, seeks change, so does the rest of the world. That’s why they are trying to make fundamental changes. A global kingdom, by no means, is a progressive vision.