The Structura Score is a suitability score, not a quality grade. A geared, non-protected note is a poor fit for a saver and an excellent fit for a growth investor, so a single blended number would mislead exactly the people it is meant to help.
Instead we score every structure three times, once for each investor profile: Conservative, Balanced and Aggressive. Each score is a 0 to 100 fit for that profile, and the highest is shown as the best fit.