What is the best practice for making man pages accessible that are installed via asdf?

I've been using asdf for a little while now, and something I have noticed is that certain man pages for certain languages / tools aren't accessible after installing such language, i.e. elixir for example.

Presently I am using asdf v0.4.0 on macOS 10.12.6 and macOS does a little trickery to get the man pages loaded. For one, if a MANPATH environment variable is set the paths specified in /private/etc/man.conf are no longer searchable.

What does this mean? I.e. if I install the homebrew version of git it's manual / man page will become accessible via man git. However if I add say $HOME/.asdf/installs/elixir/1.5.2/man to an environment variable called MANPATH then I can no longer access the man page for git using the command man git.

The trivial solution that I have come up with is to symlink the $USER specific man pages for various languages I have installed via asdf to /usr/local/share/man which then makes them accessible, and I can run man elixir and man git.

However when I installed python 3.6.3 via asdf it was intelligent enough to add the man pages from my locally installed python and link them to the proper path. I have no idea how python set this up, is it something specific to python or something specific to the asdf-python version?