SHAFAQNA – The Grand Ayatollah Shahroudi answered a question about following a Marja Taqleed.
Question: Must a Marja Taqleed (religious authority) be followed who is known to be the most knowledgeable? For example when it is well known that Mr A is the most knowledgeable among Maraje, can’t Mr B be followed?
The Grand Ayatollah Shahroudi: Those who want to recognize a learned Mojtahid, must consult with experts who are able to recognize the learned one; and fame alone is not enough; of course if there is a possibility that they (Maraje) are all learned, and the person who wants to choose one (Marja) to follow, and sees them all as equal, can follow any of them.
Source: PERSIAN SHAFAQNA