The phrase "deep bench" usually means having a team or group of people who are highly skilled, talented, and experienced. It suggests that there are many capable individuals available to handle tasks or challenges effectively. Full definition
We have struggled with shallow shallow benches or deep benches of mediocre / ill - fitting players. (sbnation.com)
... What are we going to do with our young deep bench guy next year? (sbnation.com)
Especially since I tended to grow attached to and use the same characters over and over again, never developing a particularly deep bench. (grantland.com)