How to get faster completion if I make zsh assume what I've typed so far is correct?

[paxunix <paxunix@xxxxxxx>]

Why does zsh have to glob every directory along a pathname in order to 
find completions within the final directory?  For example, take this case:

/one/two/three/four <TAB>

If I set -x, the output after hitting TAB shows zsh retrieves all the 
subdirectories within one, two, three and four.  I would like zsh to 
only bother globbing in four to find the files that I'm looking for--it 
should assume that whatever I've currently typed is correct and it ONLY 
needs to look in four--there is no need for it to know anything about 
the contents of one, two or three.  Is there a style setting or an 
option that I can use to do that?  If two, three and four are NFS, it 
can often slow down completion a lot--particularly if there are a lot of 
files in them.

--
Shawn Halpenny