The situation is similar to Jung's types. More correctly to think them as strong and weak parts equally.
It's accentuations. Some traits become good but in this process happens the degradation of opposing/suplementing traits. The better are strong traits, the worse become weak ones.
The problems of weak regions mb tried to be fixed. For Jung's types there were some concrete ideas - to make the work and studing in weak regions, duality relations.
Should be the ways for Enneagram types too.
If to describe any opposing traits - the situation should be similar. A coin with two sides.
This mb done with subtypes of E-types or anything else. Any strenght is the weakness. Dark side mb not evident and then needs to be found.