Sure, Seth MacFarlane, Alex Borstein, Mike Henry, Mila Kunis, Seth Green and Patrick Warburton are all real people, but you don’t necessarily correlate them with Peter Griffin, Lois Griffin, Cleveland Brown, Meg Griffin, Chris Griffin and Joe Swanson in the same way you see Kevin Hart on the big screen when he’s playing a comedic character.
In the past, Seth MacFarlane has spoken out about some of the “protections” animation has simply because it is putting jokes into the mouths of characters who don’t actually exist as real people.