I don't think they are planning to use Dragon capsules for Moon landings. They want to use their new Starship and probably equip it with some extra rocket engines near the top of the spacecraft so when landing it won't kick up dust and rocks into Moon orbit and beyond (yes, that would happen with the rocket engines at the bottom because Starship is so big!)
That assumes the potentially chaotically turbulent, expanding blast of exhaust gas propelling these rocks only imparts a single instantaneous linear impulse. It's possible some rock fragments might be kicked up from the surface, and then accelerated laterally away from the landing site by the gas cloud.
Perhaps? Delta-v from the surface of the moon to orbit is about 1.6 km/second, though debris from a landing would be approximately instantaneous thrust, which doesn't allow insertion into an orbit.
