[quote name='Kirin Lemon']That's an exaggeration. But really, if you actually spoke Japanese, you'd realize there's a similar overlap in the Japanese dubs as well.[/QUOTE]
Yeah, I agree; that's a pretty hefty exaggeration, and I've found that you don't even need to know Japanese to notice the overlap of Japanese voice actors — it's based on how much you watch in a given language. The more shows I watch in Japanese (due to watching most current shows each season), the easier it is for me to recognize voice actors. I may not know all of their names, but I sure can recognize their voice. And it can lead to the same thing ssjmichael is referring to; sometimes it's a little jarring to hear someone's voice who I recognize as a particular character come out of the mouth of a different character. It's like with all of Rie Kugimiya's roles; her voice usually sounds like Taiga from Toradora, Happy from Fairy Tail, or some combination of the two whenever I hear her in other roles, like Aria in Aria the Scarlet Ammo.
Basically, there's nothing wrong with English dubs concerning actors being used in different shows.