Larger planets eg. Earth, Mars $( e< 0.01 )$ have almost circular orbit, whereas orbits of smaller planets like Pluto ($ e \approx 0.25 $) and smaller entities like comets have much larger eccentricity ($ e \sim 0.9 $).
Is there any reason why very small bodies have larger eccentricity?
Once something is in its orbit, its eccentricity does not depends on its mass (depends on the initial energy and angular momentum). But does mass statistically play any role determining the eccentricity when multiple bodies are formed, say, due to a collision?