Because your definition of "Value" is uncontroversial and customary, unlike your definition of "linear graph"--I have met it in your article for the first time. Granted, my knowledge is limited but that's my point exactly: if you bother to introduce the most basic concepts that your readers are most likely already accustomed with, then also please introduce the advanced concepts that you're about to discuss. If you feel that it makes the article too long, maybe consider removing the trivial definitions of the basic concepts, but not the other way around.
I don't want to come off sounding aggressive or rude, and in fact I've read some other articles on your site with great interest, but this particular one leaves a bit of a taste of a maths article written by a crackpot: it starts with talking about what is a number, what is addition, talks about how numbers can also be multiplied and divided, a-a-a-and then in a blink of an eye it goes into very remoted areas of the number theory which may not actually exist (at least Googling them doesn't show anything relevant).
In fact, googling "linear hierarchy" suggests that it's a term from biology, and it doesn't describe a graph or a tree at all: "In a linear hierarchy, there is one individual who dominates all the other group members, a second who dominates all but the top individual, and so on, down to the last individual who dominates no one" (Ivan D. Chase, Kristine Seitz, "Aggression", in Advances in Genetics, 2011). So "linear hierarchy" is apparently a linear (or "total", as it's also called) order, and it's actually consistent with the customary definition of "linear data structure": the one that arranges it's elements in a sequence, so arrays and linked lists (in fact, those used to be called "linear lists", see Wirth's "Algorithms + Data Structures = Programs" from the seventies) are linear data structures, but trees and graphs are not.
To sum it: your usage of the term "linear" seems to be novel, and so it's confusing for someone who hasn't met it already, and arguably most of the readers haven't, maybe define it, even at the expense of defining what a "value" or an "agent" is? Those words you use in their customary senses.