Their yellowish eyes were fixed upon Harry’s wand, and they looked scared. There might be a lot more of them than there were of him but Harry could tell, by the looks on their faces, that they knew no more magic than the giant squid did. (Harry Potter 4)
I couldn’t find this expression in my dictionaries, so I went to a Google search. Here are some examples.
What about those who wanted to use more and more energy and not worry where it was coming from? There are a lot more of them than there is of him. And it is all their fault as well.
There were a hell of a lot more of them(termites) than there was of me but I had chemicals on my side.
I’d like to know especially the following points.
What is the meaning of the “more”? (Number of people? Chances of winning?)
Why do some examples say “than there were of him” and others say “than there is of him”? (I mean it plural-singular question, not tense)
I'd appreciate it if you could help me.