Re: They're looking at this now?
"Aren't the parachutes needed for the projected larger payloads to be delivered to Mars?"
Yes, the ones already used were for much smaller payloads.
This mission is much heavier than anything that's gone before and needs more aerobraking as a result. That means a bigger parachute deployed higher up, at higher speeds.
Almost all missions have used parachutes at some point in the descent, just not necessarily all the way to the ground, and preferably not to negative altitudes.