Why can't groups share quantity in warehouse?

[bloggus]

I have different groups of shops, because I have to treat them differently, and need them to use the quantity of a product in one warehouse.

 

Group A

- shop AA ->product A -> warehouse A

- shop AB ->product A -> warehouse A

- shop AC ->product A -> warehouse A

 

Group B

 

- shop BA ->product A -> warehouse A

- shop BB ->product A -> warehouse A

- shop BC ->product A -> warehouse A

 

 

All shops have the same product and I want all of them use the quantity in the same warehouse with the advanced stock management enabled.

 

 

As I have understood it is no problem to share products over different groups.

 

But it is not possible to share quantities of a product over different groups even when the same warehouse is selected.

 

Why?? Is there a way to solve that?