The rocky planet sizes between the Sun and Jupiter are small (Mercury), big (Venus), bigger (Earth), small (Mars), and unfinished (the asteroid belt). Is this just random chance or is there a theory of planetary formation that explains why, within Jupiter's orbit, more mass accumulated in the midway planetary orbits and less in the inner and outer orbits?
The answer to "Why are rocky and small planets nearer to the Sun whereas big, gas giants are farther?" question doesn't answer my question - although it might explain why Mercury<Venus<Earth.