Wrote a long thing, somehow managed to close the tab.
Chuck Huber said to Monica and Ron "Sean and Sabat won't be there for you in court". This strongly suggests they are two of the three people. Since they didn't identify Renfeld until later, that may mean these two are only for Iago and Igor. Sabat and Sean hate each other, which aligns with the hints as well.
Most likely line up:
Iago - Sabat, someone who apparently has been making enemies as he walks along at the top of the pile, seems to have complete control of the Texas dubbing scene and influence outside of it as well. Thinks he's a smooth operator and a manipulator, may believe he can get away with this by lying and using others.
Igor - Sean, a pathetic, miserable little existence. Hates Sabat but still has to put up with him. Has in the past committed TI over petty reasons anyway. Would need someone like Sabat to bill his lawyer. Too clueless to realize he's Igor.
Renfeld - Skye, A useless nobody who insists on believing she's important in extreme excess beyond what she actually is. Is butt-buddies with Monica, Ron, and Sabat despite - again - being completely unimportant and a nobody. Hasn't done anything effective, but insists she's part of 'the conspiracy'. Has Sabat (here Iago)'s favor, too stupid to know she's been caught.
There are a few issues with this casting.
Sabat - has too deep a voice, is principal - not vice-principal - of Okatron, hasn't been caught flexing his money online yet. Has been caught doing crap several times, making it harder to believe he actually thinks his hands are clean. Unclear if his renovation has already been paid for or not.
Sean - Has flexed his money online. Doesn't appear to have actually done anything, so it's rather odd for him to be cast as 'Igor' who does all the dirty work for Sabat. Sabat has been caught doing things like spreading defamatory things about Vic in private and swinging TI, while Sean has only been caught with a stupid Youtube video that insinuated Vic was a pedo.
Skye - She's never done anything of any use. Even Marzgurl has been more effective at doing damage to Vic than her. Renfeld may have male pronouns.
A wild take would be flipping Sean and Sabat because of the money flex. The last possibility is bumping Sean and Sabat down one rank on the list, and an even bigger, more powerful figure is Iago. The issue with this theory is that Nick and Ty, despite actively hating Iago, haven't hinted at a more powerful figure in the shadows basically at all.