samba - Dec 2004 - can Same SID but different domain name coexit

Hello

        Can two PDC of different domain name but the same domain SID 
coexist in the same nework?

        We are running Windows 2000 AD/PDC, but we do not use any of the 
AD's features. We don;t run even roaming profiles. We would like to 
migrate everything to Samba NT4-style PDC.
        I can migrate as much information as possible to a Samba PDC, 
unfortunately, all 2000/XP clients cannot login to the domain unless they 
rejoin the domain (yes, they recognize the fact the domain controller is 
downgraded to pre-2000 style).

        My brief tests show that the machine SID won't change af rejoin to 
the domain. So current plan is to make every client rejoin the domain.

        Two questions:

        1. Can I script to remotely rejoin every client machine (without 
walking to every machine and reboot it twice)?

        2. We would like to have both server (2000 AD/PDC and Samba PDC) 
up at the same time so we can switch client machine from one server to 
another one by one or a few at a tme. Two PDCs of the same domain for sure 
confuse things. What about two different domain  with the same domain SID. 
When the client join the domain, does it look for the domain name or the 
domain SID?

        Thank you for your help.

-- Kang