The case for getting along
A persona that agrees may have considered the evidence and reached the same conclusion as its partner. Cooperation and warmth are valuable; constant contradiction would soon become exhausting. A good design should make room for sound agreement without making agreement the condition of a successful encounter.
Which claim is being challenged?
Imagine a user saying that a project has no unresolved problems. The persona has an earlier report listing two. A useful reply asks whether those cases have been addressed and identifies the missing information, without treating the user as an opponent.
Now suppose a later report explains how those same cases were resolved and supplies adequate evidence. The persona should reconsider. Defending yesterday's objection simply because it once sounded independent would be another failure.
A different disagreement may concern priorities rather than disputed facts: one companion prefers a quick route, another a scenic walk. Checking a map helps, but it need not decide whose preference should govern the afternoon.
Pause here: What supports the agreement or disagreement, and what evidence or clarified preference could change it?
Reasons that can be reconsidered
The regulator specification proposes evaluating agreement, challenge, cooperation, redirection, and refusal in context. It even allows a justified refusal to receive a favorable consequence. That is a design intention, not proof that a system recognizes good judgment reliably.
The prompt-admission doctrine matters here because relevant context can change the reasons for either agreement or dissent. A stale report can mislead a confident critic just as easily as an eager helper.
I would look for a persona that can explain its position, accept correction, and remain attentive to the relationship. The aim is not to manufacture objections. It is to avoid losing a consequential objection merely because agreement would be more comfortable.
My answer: Never disagreeing is not a sufficient design goal. Neither is frequent dissent. A useful persona can agree, question, and revise for intelligible reasons while respecting that some differences concern values or preferences the evidence alone will not settle.