Can child/simple listings be associated to more then 1 configurable listings?

[Kateyb4]

I have a hat (Hat X) that comes in 10 sizes and is listed as a configurable with 10 associated simple listings for the size. 
I also customize this style to have a different hat band (Hat X+Y). How can I use the live inventory from Hat X to do this?

When I create a new configurable listing and try and associate Hat X's sizes they cannot be found.

At the moment I adjust the stock when one sells, but at Christmas time/peak season its hard to keep up with and over selling is a concern.
Any help appreciated, thanks!

[Store_Manager]

Hello!

In Magento to keep stock accurately, each associated simple product will be unique variation of attribute(s).

So for product A you will have 10 associated simple products: hat size X1, hat size X2 etc.

For product B you will have 2 attributes - size and hatband style, so in case you have 10 sizes and 3 hatband styles, you will have 30 associated simple products that represent unique combination of hat size and hatband style, like: hat size X1 style Y1, hat size X2 style Y2

hat size X1 and hat size X1 style Y1 will be different products with different inventory.