How do the Count and Villefort veiw fidelity in the same way?

Which Villefort do you mean? There are a few.

I meant to say Monsieur de Villefort. Sorry if I was not clear

Both these guys have their own set of values. They live by them and die by them. I suppose both men had fidelity to people they cared about but I would say their real fidelity lay with each other. Both men were completely obsessed with ruining each other.