that is not allowed. You cant share berths in that fashion in a reserved coach unless and until allowed by tte before boarding.
wl passengers cannot travel in partially confirmed ticket even though their names appear in charts. If its e ticket, you can get a non travelling certificate from tte and send them to irctc for refund after filing a tdr online. In case of prs tkt, you can cancel wl pax across the counter or ask tte before boarding reserved coach regarding wl pax