In your thought experiment, the entire country is extreme one way or another. If this country used the Borda method, it seems like a moderate would win every ti

In your thought experiment, the entire country is extreme one way or another. If this country used the Borda method, it seems like a moderate would win every time, despite the fact that there are no moderates in the entire country. Under IRV, the country would probably regularly rotate between extremes, which seems to correspond more closely to the actual makeup of the electorate. If a country is mostly moderate, it should have a moderate government. If a country is polarized, both sides should be represented in government. This is especially pronounced if we suppose that the "moderate" party isn't just the middle of two extremes, but actually has some distinctive characteristics of its own. For instance, imagine that there's a liberal party, a conservative party, and a single-issue party that advocates for the interests of farmers. Supposing a split like you proposed, with the farmer party as the "moderate centrists" it seems like the government would perpetually dedicate most of its money and energy towards agriculture, even though no voters particularly cared about that issue. It really seems like your preference for Borda is based on your own preference for moderate politics, not on any desire to faithfully represent the electorate.