If psychiatric np's get little psychotherapy training in their programs, how do they practice as psychotherapists when lpc's need years of supervision?

Maybe not at all: Pardon my bias here. Many Mental Health practitioners these days mostly prescribe based on the patient's or caregiver complaints. They don't do psychotherapy. Your query includes a likely reason - the cost of training. If it is a focus on psychotherapy you seek - consider a Ph.D., PsyD, LCSW or similarly trained pro. The medical degrees at all levels tend more toward Rx's as primary tool. Best!