[Samba] cifs + uid confusion

[Neal Becker]

I was hoping to switch from nfs to cifs on my linux systems to get away from
the need to sync uid/gid.  I am surprised to find:

uid=arg
 sets the uid that will own all files on the mounted filesystem. It may be
specified as either a username or a numeric uid. This parameter is ignored
when the target server supports the CIFS Unix extensions.

I don't understand why.  I thought getting away from this obsolete model
(needed to sync + identify users on different systems by uid) was a feature
of samba.

Is there a workaround?

These are all modern linux systems (clients and servers).