What I'm saying is that in Jung's system, there wouldn't be any true "ambiverts", because an equal amount of introversion and extraversion reflects a lack of discrimination of opposites, as both of them are "fused" together. From what Jung says, one of them would have to take the secondary position.
I can use my right an left hands simultaneously and sometimes one may be the preferred to make an action with and sometime the other, and (hopefully) they can often work together. If my right hand is a bit stronger and cultivated in certain ways, my left one is a bit more useful in some circumstances and has a bit of a touch that my right one has not the same feel for. Is there any reason for them to not want to work together?
I see myself as a being of wholeness, and who is to say which part of me is primary or secondary? Cannot the same mind that discriminates also unify?