The happiest nations in the world show us that more colors at the table lead to better outcomes.
The example that is perhaps easiest to see is with a red-and-blue system embracing the car and with society then following that direction.
Yellow is transit, green is the bike, and orange is condensing housing more in cities, just as examples.
When red and blue are in control and no one else around, then they may deliver more or they may deliver less for the car, but both are seeing the car as the one item they need to focus on. The discussion is focused on the car.
When orange, yellow and green are also at the table, then the discussion will not eliminate the importance of the car, but it will influence the focus on the car by focusing on transportation in general from a wholesome perspective. It does not mean that green will get its way, but the outcomes will be tinkered with, and each tinker is generally speaking an improvement.
The presence or absence of green, yellow and orange changes the dynamics, changes the outcomes.
I hope you agree that a full-color council will make smarter decisions than just a red or just a blue council would.