So here in the Parshah of Gedolim questions like these arise.
I don’t know the real answer myself, if there even is an answer.
But I can tell you that the Agudah board decides who is a Gadol, as if they have any right to put checks & x’s over people.
And it really depends, because some people consider a gadol to be somebody who does a lot of chesed and learns Torah and is “a giant of a man”.
Some say it’s Roshei Yeshiva, which I’m not really maskim too this pshat, because who gets to chose which Yeshiva is prominent enough to have their Rosh yeshiva be called a gadol? The yated or the moetzes?
P.s. Maybe I said something possibly controversial in the latter statement, but please, you know who you are, don’t rip on me for it.