1. When Cash votes in a circle for three or four people, everyone just yells that he's Mafia and therefore changes his votes (as if there's some connection). Chron would have figured it out if Areg hadn't hinted directly (although he might be lying, keep that in mind!).
2. It's not necessary for the Mafia to allow the victim to vote only against three Town members. More likely, they'll include one Mafia member in that group of three to create confusion. For example, the one who won't kill for a long time.