I suspect that Cadsuane has her core group of Aes Sedai who have useful skills that she can use or personalities that she trusts. Strenght in the One Power is not the deciding factor as I think Cadsuane looks beyond that.

For the rest there are AS who suddenly don't know which way to jump. Any of them who encounter Cadsuane and who know her either personally or by reputation would probably sound her out on what she things they should do. I don't think she is the actual leader of the group but they would listen to her advice and give it a lot of weight.

If there are about 300 neutral AS not all of them would have had a chance to speak to her and are probably rudderless or sticking together in small groups for safety.