[Samba] smb.conf for around 2500 users

[steve]

Samba4 with Linux and Windows clients wanting to get the same home 
folder data.

Hi
A college has students arranged with Linux home directories according to 
which year they belong to and which class within that year, a or b or 
whatever, they belong to e.g.:
/home2/students/year7/year7a/student1
/home2/students/year7/year7a/student2
...
...
/home2/students/year13/year13a/student2500

To get at the same data on windows, I was thinking of a share for each 
of the classes e.g.
[year7a]
path = /home2/students/year7/year7a
read only = No
browsable = No
...
...
[year13a]
path = /home2/students/year13/year13a
read only = No
browsable = No

and mapping a drive letter to the share e.g.
map Z: to \\server\year7a\%USERNAME%

That would make lots of shares but would make it readable to non admins.

Is there a limit on the number of shares per installation?
Any other ideas of how to go about it? e.g. I thought about OU's but we 
do not want to administer from Windows.

Cheers,
Steve