Wrong Fit
As a mech designer, Ves was already aware of the concept of utility.
However, third-class mech designers viewed utility in a much more limited fashion than second-class mech designers.
The limited resources and technology at his disposal forced Ves to neglect utility in favor of focusing on the other three aspects of his products.
Offense, defense and mobility.
When stripped of all of their complexity, every mech had to offer a winning combination of these three aspects.
Of course, a good mech was not simply a package that scored high on all three aspects. A mech design was much more complicated than that, though many laymen still referred to aggregate numbers such as the mech performance index to get a quick evaluation of a mech.
What made a mech truly great was how well they fulfilled their roles. Having good offense, defense or mobility was often one of the main requirements for many roles, but they were not the only ones that existed.