Yes, dynamic pairs offer the most opportunity for direct conflict. While not strictly binary, they come the closest to representing binary choices. We chose dynamic pairs as the basis for the Dramatica structure because they are a key component to linear thinking, which mirrors the bias of most American culture. In Dramatica terms, the Dramatica structural model is based on the Male Mental Sex style of problem solving (linear). Since all audiences for Dramatica can understand linear thinking, we chose the binary bias for Dramatica.
The basis of Dramatica is that stories are analogies to a single human mind trying to resolve an inequity. In fact, stories are more than analogies, they are maps to the layout and functioning of human problem-solving. Part of the design of the structure includes both binary and analog elements. Not only does binary fit the Western bias, but it also works well with computers for creating software.
The Overall Story and the Relationship throughlines represent objective and subjective views of groups. The Influence Character and Main Character represent (somewhat) objective and subjective views of individuals. That is why they are balanced that way as dynamic pairs.