I like Scott's Mistake Theory vs Conflict Theory framing, but I don't think this is a complete model of disagreements about policy, nor do I think the complete models of disagreement will look like more advanced versions of Mistake Theory + Conflict Theory.
To recap, here's my short summaries of the two theories:
Mistake Theory: I disagree with you because one or both of us are wrong about what we want, or how to achieve what we want)
Conflict Theory: I disagree with you because ultimately I want different things from you. The Marxists, who Scott was originally arguing against, will natively see this as about individual or class material interests but this can be smoothly updated to include values and ideological conflict as well.
I polled several people about alternative models for political disagreement at the same level of abstraction of Conflict vs Mistake, and people usually got to "some combination of mistakes and conflicts." To that obvious model, I want to add two other theories (this list is incomplete).
Consider Thomas Schelling's 1960 opening to Strategy of Conflict
I claim that this "rudimentary/obvious idea," that the conflict/cooperative elements of many human disagreements is structurally inseparable, is central to a secret third thing distinct from Conflict vs Mistake. If you grok the "obvious idea," we can derive something like
Negotiation Theory(?): I have my desires. You have yours. I sometimes want to cooperate with you, and sometimes not. I take actions maximally good for my goals and respect you well enough to assume that you will do the same; however in practice a "hot war" is unlikely to be in either of our best interests.
In the Negotiation Theory framing, disagreement/conflict arises from dividing the goods in non-zerosum games. I think the economists/game theorists' "standard models" of negotiation theory is natively closer to "conflict theory" than "mistake theory." (eg, often their models assume rationality, which means the "ca