>>11718814 LB
It's not like what you're thinking, anon. You misinterpret the meaning (understandably so). The Circuit Courts of Appeal have plenty of judges (note - judges, not justices).
The justices are assigned to Circuits to review petitions for orders which come to the Supreme Court from the assigned Circuit Court of Appeals. Keep in mind that the USSC doesn't just do the "hear case, issue opinion" thing that everyone sees. It also issues temporary orders, like injunctions and such, just like any other court. Alito just did it a couple weeks ago in the PA case.