so, i think it's already a common understanding that tom won succession in part through his deep understanding of everything laid out in that original post. hierarchies. he knows his place very well, ie he knows whom he's under.
-and because he knows how to utilize his position on the ladder, he's also able to climb it. particularly through shiv.
...which i feel begs the question: why? why is tom ultimately more intuitive with this system than the roy siblings?
there are multiple answers, including 1) class - tom has lifelong experience climbing up whereas the sibs were born at the top and only have experience flipping between 3 or 4 rungs; and 2) tom specifically has lived outside of logan's world and in the end is contending with those other than logan anyway, meanwhile the sibs are lost with their dad gone; but what i want to talk about most of all is the answer that factors masculinity back into it, and which concerns tom as a whole person rather than simply a corporate agent:
3) tom's innate desire for other men and repression of that desire, having grown up in the midwest during the peak of the AIDS crisis, has made him only capable of functioning within a hierarchy. he has long since carved a space for himself in the framework of heterosexual masculinity and is incredibly vulnerable without it.
what i mean by this is that tom, like many men in hypermasculine environments, recontextualizes expressions of desire into displays of power as well as ritualistic displays of submission. this is common even in outright homosexual environments due to how many men spent their lives beforehand with these hierarchies being 1) the most intimate that they ever got with other men, and/or 2) the safest way to be close with men at all. within hierarchies, there are pre-established rules, and if you touch or are touched by men in ways that follow those rules - as in, you're either exerting power or knowing your place, then you're safe from the notions of true desire. the existence of the hierarchy also implies that you will do both, once you're past the absolute bottom rung. experiencing the control of other men is simply a trial that you endure in order to be in their place one day.
and once you do this for a long time, you become blind to what desires even are. you become essentially a high-functioning depressive.
but tom also snaps on occasion, effectively utilizing his power at those times... and what's interesting is that in spite of his need to not be vulnerable, and in spite of his need to have the power in the situation, we see him shaken by his own actions. we see him not only apologetic for going too far, but on top of that, a consistent willingness to break the rules of the hierarchy and make someone else his equal. that someone, of course, being greg.
tom is clearly a romantic to his core, and this definitely extends to greg despite there being no formal romance between them, with his consistent efforts to bring greg up to his level. or rather, as close to his level as he can before he starts panicking. because as much as he clearly craves that partnership of equals, tom literally does not know how to comfortably exist in intimacy with another man unless he has those rules.
on multiple occasions he's shown to panic at the end of an otherwise equal (and therefore vulnerable) interaction and bring up notions of his position over greg to feel safe. what's notable is that even as he does so, they are simultaneously expressions of love and desire that get progressively undeniable as the show goes on:
and finally, for the whole of season 4 i think tom is in a constant state of panic that is partly due to how high up he's taken greg. there's the factor of not feeling certain that greg will stay once he no longer needs him (which i also would say is, itself, a factor in tom's comfort within a hierarchy), but also a general sort of uneasiness because he's just broken down a wall that was previously keeping him safe from his own desires. he's got to look greg in the eyes now, basically. the more power and mobility he hands to greg, the more tom has to acknowledge that being around him is just what he wants.
...and he's been keeping greg at this level for at least 3 months, so it's also definitely circumstances that tom wanted to keep nevermind the discomfort. we obviously don't know much of what happened between them offscreen but we do have those vague allusions to the disgusting brothers - evidently nights together at the bar, aka a place where businessmen can get drunk enough that it's appropriate to become equals. this gets more into headcanon territory but i gotta imagine that alcohol is a big factor in how tom grows to cope with the change. in the same way that you still take pain medication after an elective surgery.
of course, not only is tom still in the process of accepting the changes to his dynamic with greg, but season 4 also takes place over an extremely hectic and stressful one-and-a-half weeks, so it's all-around reasonable that tom continues to lash out to reinforce the hierarchy.
but once again, even moreso now, the way that he lashes out is an undeniable expression of attachment, of a desperate need to keep him close... of love. so undeniable that in the end, even greg fully understands.