4-2-3-1 (using MC-MC, AML-AMC-AMR) is easily beaten by 3-5V-2, but not much else.
4-3-2W-1 is easily beaten by 4-1-2W-1-2 (wide diamond) and a few other formations depending on tactics/arrows.
4-2-2-2 is versatile, but isn't very defensive.
RJ suggested the 4-5V-1 because he uses that a lot. It's good because you get a lot of coverage every where and good attacking/defensive balance. I also use this formation and find it's very easy to change to almost any formation you want.