I got the impression from the preview that one of the twins had already been captured/killed by the time the scene with Revy. More importantly, the one accuses Revy of being just the same as they are, which from what little we do know about Revy, is probably pretty close to true. With luck, we'll get some more background on Revy.
Either way, Balalaika is real scary. She's herding them exactly where she wanted, until the two "uneducated whores" interrupted. I wouldn't have been surprised if the twins would have ended up right at the fountain she's sitting on.
Could anyone honestly say they didn't expect Revy and Eda to say "We'll take it all...and their lives" ?