Trading Teahen for Helton sounds good to me. Obviously, neither of these players are likely to really impact your season all that much, but despite Helton's age, I'd agree that he has a better chance of producing this season. If your league counts BB or OBP Helton will definitely be of value there too.
I'd prefer Sandoval over Salty and Hernandez too (not sure why you have 2 crappy catchers, haha). However, someone I might like more than all of these guys is Clement, if he's available.
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