The nss_wrapper is currently in section 1. According to man-pages(7), this section is for "commands that can be executed by the user from within a shell". But there is no command called "nss_wrapper".
I would rather expect the nss_wrapper manpage to be in section 7 ("Overviews of various topics, conventions and protocols, character set standards, and miscellaneous other things").
I thought that section 1 is fine, cause you can execute any command in a shell together with nss_wrapper. :) It is not a library you can link nor can you run it without starting another process. So on one side section 1 fits on the other it doesn't.
I will ask the other Samba developers ...