How do I reorder/rearrange the input languages on High Siera?

I saw some recent questions on how to rearrange the input language order in the drop-down menu. The easiest way

to do this seems to be the following: You first delete everything in the list (hopefully not a very long one), and then add them back in reverse order. In other words, if you want to see in the drop down menu the languages A, B and C, in that order, then add C first and A last.