You absolutely can just start aerobraking if you have maneuverability on the launch vehicle (because it's small, packed with fuel, and limited duration). Regar

You absolutely can just start aerobraking if you have maneuverability on the launch vehicle (because it's small, packed with fuel, and limited duration). Regardless of what orbit you start from, you dip into the atmosphere, deploy your payload from there, voila. Now anything you dropped has to deal with a furnace of superheated air, and the question of whether it's possible to have control in those conditions, but it's definitely going to de-orbit. And the atmosphere is going to supply most of the energy, rather than direct retro burns from the delivery vehicle.