Virtualization Scenario DAX 2012

We're passing through the following scenario into a customer in which we're implementing DAX 2012:

They want to virtualize the customer and vendor table in a way that whatever company is used to create a new registration, a single numeric sequency must be respected.

In DAX 2012 there's a functionality to use Shared numeric sequencies (like it's used for items), however when I tried to set up this shared sequency for customer and vendor ID, AX did not allow it.

We had these 2 solutions which were reproved by the customer:

1. Define (as a process) 1 of the existing companies to be used to create all new vendor and customer registers.
2. Create a" Register Company", in which all registers should be done.

The solution we're studying now is to create a numeric sequency for vendor and customer ID that is set up for a company (and not shared) and choose the virtual company. Proceding like this, Ax seems to be respecting the same sequencies for vendor and customer ID's in any company.

Have anyone gone through the same situation?

Tks for the attention.
Ana