Sort these bond ratings
ES6, 71 65 bytes

a=&gt;a.sort((b,c)=&gt;r(b)&gt;r(c)||-1,r=s=&gt;s.replace(/[^A-z]*$/,"z$&amp;,"))


By inserting a z after the letters and suffixing a , we just have to sort the strings lexically.

Edit: Saved 6 bytes thanks to @user81655.