media-fonts/droid-113-r2 installs /usr/share/fonts/droid/DroidSansFallback.ttf and app-text/ghostscript-gpl-9.05-r1 installs /usr/share/ghostscript/9.05/Resource/CIDFSubst/DroidSansFallback.ttf Please use symlink like stellarium ebuild does. There is only one problem: ttf from droid has version 2.31, but ttf from ghostscript-gpl has version 2.52a.
a) We dont have such a policy yet. b) We will not mix versions.