I've seen videos of people reaching Feudal as fast as 5 minutes by luring Boars ASAP, sometimes with Scouts. I've never seen competitive players do it, though, so I'm guessing not but is there any small, possible use for a "Fast Feudal"?
You make fletching instantly too. You make your eco like.One problem with super early feudal times is that you will have a hard time keeping up vill production.
That being said, you can do a pop 17 trush with Japanese while keeping up vill production or pop 19/20 teut trush like pyc_hawk obviously. I think super fast archers is less viable since archers without fletching take significantly longer to kill vills (especially if they're running from them) and one your opponent reaches feudal, he can shut it down easily with skirms.
With mong it's obviously a little different since you have all the excess food.