The 10 samples tubes which are being dropped now are a backup in case perseverance fails to deliver the actual samples to the lander which are persevered under its belly. In the event of failure by Perseverance, NASA had planned to send helicopters to pick these samples and deliver to the lander and later loaded into the Mars Ascent Vehicle and brought back to Earth - mote details here - https://youtu.be/1iQU58GnFZQ