Doesn't L HAVE to be before N? So how can G be sixth?

I was confused about this same thing as well. How do we know that N can go after G? I didn't understand this.

there is no relationship between N and G, that we can say that Nasser earns more than Glassen. in rule two Lopez earns more than Nasser, but it does not establish relationship between Nasser and Glassen, neither it creates a restriction that L must come before N. so in our possible hypothetical we can place N and after G.