Yeah, he has two origin stories.
One is he is a member of a mafia family who sees his mother assassinated and takes up ventriloquy as a form of therapy until he loses it later in life...
The other is he kills a guy in a drunken brawl and goes to prison. In prison he is cellmates with an inmate who carved a dummy from the old gallows tree after it was struck by lightning. Arnold immediately believes the dummy is speaking to him and so he kills his cellmate to "free" the dummy. The rest is history.
I think both stories have merit, so my personal take on it would be that as a child he was a part of a gangster family until his family was massacred. Arnold was spared and raised by another family, but the trauma ate at him until he killed a man in a bar as a young man... and then goes to prison, kills another man for Scarface, and attempts to rebuild his original family's empire, except now with Scarface serving as an outlet for his pent up aggression.
I also like the idea of teasing that there might be more to Scarface than just a simple puppet. Like, he might actually be alive or a magical conduit of negative energy or something. Don't be blatant with it, but tease the possibility that Wesker isn't just a crazy old man who carries a toy around.