My impression after reading this is that the author needs a better git client. magit, SourceTree, or Fork (my personal favorite at the moment) let you stage ind

My impression after reading this is that the author needs a better git client. magit, SourceTree, or Fork (my personal favorite at the moment) let you stage individual lines and chunks, which is life changing. If you find a typo or something you want to be in another commit, stage that line and commit it and carry on. Use rebase and cherry pick later to move commits around as you want.