Hi,
just for my curiosity I wonder why the numeric UID values matter at all, for example:
I believe file ownership is tracked by numeric UID rather than user name.
So, for example, if you multi-boot, a file owned by user 500 in one system will be owned by user 500 on every other system, even if it does not correspond to the same user name.
That's been my experience anyway, and an occasional issue.
dan