Since I don´t know how far you are, I can´t recommend pokemon for you to pick up. Building with the ones you have, this team seems balanced:
Aegislash (stance change, adamant; swords dance, king´s shield, shadow sneak, sacred sword - item: life orb)
Incineroar (Intimidate, adamant; darkest lariat/knock off, flare blitz, X, X - item: assault vest )
Rotom-Wash (levitate, modest; hydro pump, discharge, will-o wisp, pain split - item: leftovers)
Chansey (natural cure, bold; soft-boiled, toxic, heal bell/aromatherapy, seismic toss - item: eviolite)
Crobat (infiltrator, adamant; brave bird, X, X, X - item: X)
Garchomp (rough skin, timid; bulldoze, outrade, X, X - item: X)
"X" means it´s not too important.