“… a gadol hador must also have extensive secular knowledge, etc.”
In which “Handbook for (Prospective) Gedolei Hador” does it say that? I’ll reiterate what I wrote previously. It’s not a popularity contest or an election. It’s the consensus of leading rabbonim at any given time who among them is the biggest expert. The “vote” and even the opinion of laymen and certainly amei-ha’aretz do not count for much in arriving at this determination.