Me too, though I have them setup on shell rather than .gitconfig. Saves that one space after 'g' :)
The ones I find myself using most are 'gru' for git remote update, and 'gka' for "gitk --all -500 &". (The -500 is there to prevent my laptop dying when I run gitk with --all on the Linux kernel repo without second thought...)
Now you could decide to systematize the "grammar" of your shortcuts somehow, and, well... it's definitely an idea people have had before. ;)
https://magit.vc/screenshots/popup-diff.png
Not an Emacs fanboy, by any means: I use Spacemacs. Magit is objectively excellent, though.