Nope, never heard about that rule, even google search does not give me a clear result regarding the golden rule of consistency and navigation elements. Will search deeper.
Now it gets more clear, why You think that this change should be done. Thank You for answering me.
However, I would hope, that if gidgreen adopts Your right suggestion, that at the same time a plugin or switch in core will be available, so one can maintain the old order of buttons without rewriting the core files again.
By the way, I am sure that You are right with Your suggestion, I just wanted to understand, WHY you was asking for that design breaking change.
Now I know it, thank You so far.