It turns out that placing similar config files (i.e. bspwm-related) in
the same directory is not the way to go about handling dotfiles since
each config file (or dotfile) *should* manipulate only a single program.
This was not the case back when I used urxvt (which would require the
old method of .Xresources), but now that I understand more about how
*modern* dotfiles work (with $XDG_CONFIG_HOME), separating dotfiles by
program became the obvious choice.
Realistically, you won't need my wal config if you are not using my
bspwm setup, since wal does a good job at otherwise changing most other
color schemes that you may find in, e.g., a GNOME or Plasma setup.
Also, after some testing, it turns out that my previous assumption about
systemd was wrong. Placing a service in default.target.wants directly
will cause the service to instead not be recognized by systemd.