The way I see it, revealing your roles right from the start doesn't really help with anything.
Since roles aren't exclusive, there is literally no way of knowing if someone's role is true or not until they prove it by using their abilities.
Roles like armed driver requires you to kill someone to prove your role so it's pretty risky and doctor role requires you to revive people. We can use this to confirm people's role by having an armed driver kill someone and then have the doctor revive them, but that's a waste of an ability. So even though it's a unique role, it's not impossible to steal those roles if you're a mafia since they won't have to prove their roles until a special occasion arises.
So the easiest roles to claim would be either Alien or just normal drivers.
It's obvious that we can have multiple vanilla drivers and as alien, you have a perfect excuse if your role is ever to be revealed.
If I were a mafia it would be super easy for me to claim those roles and no one would bat an eye.
Sure, I'll be in the suspicious list too since those roles would be the easiest to assume. However, there are also quite a number of others who've also claimed those roles, so it's gonna be hard to track down who's lying and who's telling the truth. That's why I'm a bit against revealing roles since it will just gives mafias free info.
Mafias aren't afraid of us just killing off vanilla drivers and aliens to kill them in the process either, since they're the minority, meaning the chance of one of them being lynched is low if we kill off people randomly based on their roles alone.
That's why I think the majority of mafias have already claimed either alien or normal.
And now since I haven't claimed any role, if I were to be kept alive, I'd pose a threat to the mafias. They don't know my role, so they'd have 2 options.
1, keep me alive since I'm already suspicious, they want people to vote for me, but I'd pose a threat to them if I have an important role.
2, Kill me right away since they don't know my role and I could have a dangerous role.
However, I think they'd be more likely go with option 1 since even if I do have an important role, the chance of me using my ability to reveal one of them is still quite low since this is still the first round and they're still the minority.
So they'd probably would hope that I'd get vote off instead, so that they don't have to kill me and it would make people believe that they're down on 1 member.
And even if I've used my ability on one of them, my words won't be trusted since I'm already suspicious from the start.