Roleclaims are not some sort of insta-win tactic. In fact, in most mafias, they're not even a good idea. The last few mafias have been exceptions. Mass roleclaims have been the best strategies not because they're inherently overpowered, but because they happened to work based on the way the rules were set up.
In the past couple mafias - which have been exceptions, not the rule - there were very few vanilla civilian roles, if any. This means the mafia could not disguise themselves as vanilla civilians. This mafia is different in the sense that the majority (7/13) of the civilians are vanillas. If a mass roleclaim occurs, the 3 mafias blend in with the 7 vanillas, and if we lynch someone who claims they're a vanilla civilian, there's only a 30% chance we manage to lynch a mafia. In the last game, the mafia had to claim a role that was already taken, meaning we had a 50% chance to lynch a mafia, which then became 100% if we got it wrong the first time.
Simply put, the math does not work out in favor of a mass roleclaim. It's not worth revealing crucial information to the mafia just to have a slightly higher chance of lynching a mafia.
This is all exacerbated by the existence of the Cyberman role. Even if we come up with a small alliance of players who are confirmed, the mafia can easily infiltrate this alliance and destroy it from the inside.
Mass roleclaim is not worth it, seriously. If you have an important role, you need to keep it secret from the mafia.
