Greg Hirsch is a fascinating character in Succession because he initially comes across as a naive comic relief but gradually develops into an illustration of how institutional incentives can reshape a person or solidify traits that were already present.
At the beginning of the series, Greg is painfully out of place, which seems to serve as a comedic relief but also a mirror to the audience. He's awkward, anxious, frequently apologetic, and seems to show at least some moral discomfort about the behavior of the Roy family and the world he enters.
Throughout the series, he changes incrementally through hundreds of small compromises. He keeps incriminating documents when he thinks they might protect him, hedges his loyalties, and cultivates relationships with whoever seems most useful at the moment. He becomes increasingly comfortable using people as means to an end while still maintaining the self-image that he is simply trying to survive or that he's naive - until it is painfully clear this is not (or no longer) the case.
His relationship with Tom Wambsgans is central to his character arc. Tom is: mentorship, exploitation, friendship, emotional dependency, workplace bullying, and strategic alliance. Tom oscillates between humiliating and verbally/physically abusing Greg or treating him as the only person he can truly be vulnerable with. Greg, meanwhile, learns from Tom that proximity to power can be more valuable than competence or principle. He also learns that convincing powerful people you're useful can sometimes function as a substitute.
What fascinates me most about Greg's arc is that he often uses uncertainty and perceived naivety as a negotiating tactic. He rambles, asks half-questions, and leaves himself copious space for plausible deniability - which creates the impression that events are happening to him, when in reality he is often making calculated choices while avoiding explicit commitments. No one else does this in the series because perceived incompetence in perpetuity wouldn't benefit them in their image or ambitions. For the Roy family, it is not the cutthroat way they were raised, but it benefits Greg because of his position and newer entry into the world. It is not sustainable long-term.
To me, Greg might have always possessed opportunistic instincts but lacked the confidence and opportunity to employ them until he enters this world.
He seems morally hesitant, but when faced with a choice between principle and personal advancement, he repeatedly chooses advancement - and it has repeatedly benefited him.
It would be difficult for a less capable writer to create a character like this, but Jesse Armstrong and the other writers have succeeded brilliantly.
That is why Nicholas Braun's performance impresses me so much. At 6'7", he could easily dominate every room he enters by physical stature alone, yet he consistently projects someone who seems uncertain, awkward, naive, harmless, and almost peripheral. The result is a character whom both much of the audience and the in-show characters underestimate and what he is capable of until it becomes blatantly undeniable.