As for the no lisp for Noah Taylor’s similar-to-Vargo-in-function character…I think it’s a good idea to lose the lisp.
It’s presented as a joke for people to laugh at. That’s not a great thing and I can see how it would cause problems for the show, so it’s better to lose the speech impediment treated as the comedic side to a negative character. I’m trying to see it from the show’s point of view- this is only my own wondering, and I don’t know if that’s why they ditched the lisp. Just my spec.