Tom is a middle manager that has achieved a position far beyond his abilities. He knows he is out of his league, but he loves the money and power. They all do. He is also smart enough to realize he is in over his head. That is the rationale for keeping Greg, who is much smarter than Tom, around at all.
The dynamic between the children and the non-family executives is hilarious and spot on. Francis took one crack at Logan with Kendall, got crushed, and now he will both never trust any of the kids again, and is a total sycophant for Logan. Geri manipulates Shiv, Kendall and Roman all the time to preserve her place and make them the fall guy for bad things that happen. The news boss, Cyd Peach, dismantled Tom within the first 3 minutes of meeting him, but when things got ugly with the Nazi news anchor, she wanted their cover.
Other than maybe Cyd, none of the non-family executives are really "A players", but they are exactly the kind of people that you find at the top of big, family owned corporations. They got their positions through the good graces of the family, not their ability.
The show is set up in almost a Game of Thrones contest for Logan's Iron Throne.
