Thanks Misalf, noticed my sudo entry after the fact, remnant of newbier days
wwwronin file(s) in ~/.X.d. are NOT scripts, just plain text files named whatever. You can have multiple entries in a single file. Or create multiple files with a single entry in each file. The permissions are of course tc:staff, provided you're running as tc, as it's in your home directory. You do NOT need to chmod +x or anything, it's NOT a script.
So you could do...
filename: ~/.X.d./10_editor
entry: editor &
filename: ~/.X.d./20_firefox
entry: firefox &
....or just one simple file named ~/.X.d./startups containing:
editor &
firefox &