If you have a lagrangian for chiral superfields in 4 dimensions which is also invariant under SU(N) and you try to gauge the symmetry , You introduce a connection $\Gamma$ so as to make $\Phi^{\dagger}\Gamma \Phi$ gauge invariant under super gauge transformation. If $\Gamma$ is hermitian , you have introduced vector superfields into the lagrangian coupled with the chiral superfields. Now why don't we consider cases in which $\Gamma$ is not hermitian ?