I'm sure getting a real life burly red bearded Scotsman right out of a Glasglow pub to do the voice acting (there really wasn't a lot of lines for old Cait Sith anyway) wouldn't have bit into their profit margins too much.
That way you would have gotten some real authenticity
EDIT: Yeah he is controlled by a ShinRa employee known as Reeves. I'm still not sure how that all works, does he control the toy and there is a living cat on the top, is the cat also part of the toy? Very confusing but definitely remotely controlled from ShinRa headquarters anyway.