Not sure what you are asking there or trying to do. I will assume you have a bunch of chests in an arena with random items in each one.
Each arena chest could have an injector that removes all items on a signal that repeatedly pulses it and sends items to a master chest. You could have a master chest for each type of item: swords, boots, legs, … and sort the items to each master chest.
To refill, you pulse an injector on each master chest which sends the items through a series of cross junction tubes and then to teleport tubes to each chest in the game. When an item enters a tube with more than one exit, it round-robins to each one. So first item goes in one direction and second item in another. First junction can have 3 exits, and each of those can have 3 exits (9 total exits). Keep adding junctions until you have enough exits for all chests. Use sorting tubes to prevent items from backflowing into the entrance. It is important the junctions are balanced, otherwise more items will end up in chests on the side with fewer junctions.
Set the injector to sequence slots randomly and leave its filter slots empty. It will randomly pull items from the master chest and send to the junctions which distribute to each chest in the game. By using a separate master chest for each item type, you ensure that a chest won’t contain more than one of each type. You pulse the sword chest until empty, then pulse the boots chest and so on.
Flip a lever by master chests and all chests in the arena will be emptied. Verify each master chest has all the items, and restock/repair as needed. Then flip another lever and the master chests fill all the arena chests.
Poke me on irc if you need help making it.