I have confused myself with NFS4

If I have :-

A NFS4 server as such…
/shared …fsid=0 etc etc
/shared/home bind=/home etc etc

and all the users home directories are in /home on the server

Then my clients get their user info and automaps from a ldap server
home directory /home/username1
automap fileserver:/home/username1
and so on…
everything works… so far so good

Then I thought as I have 1200 home directories I’ll split them up to make it easier to use
( In the final setup it will be 2 servers with 600 each )
So I have 154 or so users in each sub directories in home

/home/2011/username155 etc

now if I change the users home directory to /home/2011/username1
and the automount to fileserver1:/home/2011/username1
It doesn’t work

but if I have users home directory /home/username1
and the automount to fileserver1:/home/2011/username1
It does

This wasn’t what I expected at first.

After some thought … Am I right in thinking that the users home directory ie /home/username1 is what the client sees
and the automount of fileserver1:/home/2011/username1 is what get dropped over the /home/username1 so to speak
so even if I made it /home/dir1/dir2/dir3/username1 on the server and the automount it would still work. That being the
case is there any performance penalty in making it go one subdirectory down as I have it or would I be better having
all the users in /home and accepting it’s a bit daunting to look at

Sorry for waffling