Original voiceactors of the Peanuts, ca. 1968.
Sally Dryer (voice of Lucy), Gail DeFaria (voice of Peppermint Patty), Peter Robbins (voice of Charlie Brown), Christopher Shea (voice of Linus).- Via Peter Johansson pic.twitter.com/DVcy0PatUM
There is gameplay on YouTube Sandy definitely used her Chibiusa voice for Patty. However it sounds like they got a new voiceactor for Yuri for the PS3 exclusive stuff. It's definitely not Troy Baker but oddly enough I don't think it's Matt Mercer either.