Okay, going back to Griffin as Takuya, I now understand what you meant by "The clip doesn't do his full performance justice"; if anything, I think you should blame my naivety for that.
With that said, I was able to find
this video, and after listening to pre-fusion Akira's voice (0:20–0:39/0:40), I feel like I'm finally convinced that Griffin would make for a decent Takuya.
Again, I apologize for my lack of experience/judgement; it's just that I've got a reasonable amount of schoolwork these days. Hopefully, though, you'll be able to understand what I'm saying.