I largely missed the conversation about Corrin's voice, but I don't think Cam Clarke's take on the character is that bad. He does a decent job providing a voice for what Corrin is intended to be, a sheltered and naive softy bound to and driven by his own principles. I think it's mostly poor writing and direction that drags the performance down.
Also, can we talk about how great Ultimate's English voice cast is? Stuff like getting Keith Silverstein, David Vincent, and Patrick Seitz to reprise the roles as Simon, Richter, and Dracula a decade after Judgement and the Dracula X Chronicles is pretty awesome. Smash's voice cast comes from all over the world and has a ton of history behind it, Nintendo really went above and beyond the call of duty.