There's a fundamental tension between the goal of having local representation—whatever failings it has, first past the post does have one riding and one person in the smallest geographical size that's possible given the way in which people are spread across the country—and proportionality. Pure PR, one giant list for an entire country, gets the best proportionality but the worst geography.
We heard from witnesses from Ireland, where they have an STV system. Ireland started off with ridings that typically had a larger number of MPs, but gradually the number of MPs has been coming down because the parties that dominate the political system have an advantage. When there's a three-member district, which is the minimum number allowed per riding under their constitution, they get less proportional results.
You can see what I'm getting at here. Four seems like a number unlikely to produce highly proportional results. Am I wrong in my concern that a riding of that size would have that problem?