I know I'm gonna get flack for this but... This is how I like animated projects made today to be done in terms of voice casting. Yes, Hamill is a long time VO actor, but he's also been and had a career as a live action performer.
Absolutely, I respect the hell out of a lot of the "name" VO workers like Maurice Lamarche, or Billy West or the grand old timers like Welker.
At the same time... I do think live action performers bring a lot more, well... realness to the performances, less, how do I say this... Less just some simple "put on voice" and more a real performance. The list of great actors and actresses from say, JLU is pretty impressive and I think the work stands for itself.
If I am honest, a lot of what contributes to how I judge an animated project, American, Japanese or otherwise is how much recycling of talent they do. I'm sorry but... It gets REALLY boring and tiring listening to the same Dozen or less VO actors do the same handful of archetypical voices they have in their arsenal.