[Space] Making a solar system with 3 (semi-) habitable planets?

[Anthony]

Originally Posted by kdtipa

Check out the scientific analysis section: "Counter-Earth"

It's missing an analysis of orbital stability. Look at co-orbital objects. I believe most of them are unstable when dealing with objects of similar mass, and the only known similar-mass example is the Janus-Epimetheus system of moons.