An often ignored aspect of a robo is its hit box. This refers directly to its physical size and how well the robo can dodge attacks. All attacks are defaulted in the center of the opposing robo's body. When an attack hits any part of the robo body, it takes damage, but it is not believed that the relative size of a given part truly has an effect on hit box. This may be related to why robo parts shrink or expand to fit their body. Before you choose a robo to use, be sure to understand how the robo's size will affect defensive abilities, and therefore attacking abilities. The larger a robo's body is, the lesser margin there is when dodging and moving as well.
An example is a Big Boy versus an Aerial Beauty; while they both have similar jumping abilities, the Aerial Beauty is far smaller.