You can also keep your configs in git and just pull.
Because that's perfectly reasonable to expect. After all, everyone has a git repo, right?
Oh okey, dropbox then? Do you mean we can not assume that arch users have a way to store away their config files?
Yeah, just do a "git init" and now you have one.
How many arch users do you imagine don't have any git repos?
I didn't. I would wager most don't.
I did a reinstall recently of Arch and the only thing I did was to copy the user folder from my old computer to the new one. Everything worked out of the box.
You could always install Antergos. It's basically just Arch + sane defaults