things that we can't have in the shops

[BG-57]

Maybe the amount of swords would stay the same. For example: BG-57 and I are FFT warriors. I become jealous of his avatar and throw our one Excalibur at him. He catches the Excalibur and puts it in his pocket (don't ask me how). Despotus (also a FFT warrior on our team) decides to join in the fun, grabs the one Excalibur, and also throws it at BG-57, who again catches it and puts it away.

After we kill the enemies, the avatar issue is resolved, and the team of UltimaLimit, BG-57, and Despotus still only has one Excalibur. Think that's what might happen, since the team shares the same "backpack"?

That's true, but Mimes repeat the same action. Suppose I didn't have Catch equipped. You'd whack me with that one sword and it would be lost from the inventory. But if Despotus was a Mime imitating your action, he'd supposedly throw that kind of sword at me.

Now the question is: would he still be able to?