Ehhhhhhh. I've seen every episode of PD several times over, and almost every character crosses the line into corruption, and it's largely presented in an "ends justify the means" manner. Beyond Voight (whose character has been drastically softened since he flat-out murdered his son's killer in season 3), Ruzek idolizes him and is happy to break every rule in the book, same with Upton, Halstead has flipped over to the dark side, Lindsay shoved her gun down a suspect's throat, we don't even need to get into some of the really shady shit Al Olinsky did, even Dawson did some really bad shit despite being the purported conscience of the unit.
Arguably, the only good-ish officers in the unit are Burgess and Atwater, and they both have their own ghosts in their closets, they're just ... less-evil ghosts. (Platt doesn't count, as she isn't in Intelligence, and even she tried to extrajudicially murder someone.)
Even though I live in Iowa, now, I grew up in Chicago and I know how shitty the bureaucracy there is, but the Intelligence unit in Chicago PD is kind of a caricature. And that's why I was incredibly uneasy when Rick Eid was announced to be running season 21 of Vanilla.