> LLMs don’t have such instincts and can potentially be instructed to present or evaluate the primary, if opposing, arguments.

It seems essentially wrong to anthropomorphize LLMs as having instincts or not. What they have is training, and there's currently no widely accepted test for determining whether a "fair" evaluation from an LLM stems from biases during training.

(It should be clear that humans don't need to be unpolitical; what they need to be is accountable. Wikipedia appears to be at least passably competent at making its human editors accountable to each other.)