IMO - Personal choice.
I like 4 fletch 3.75" which equals out to the same 15" total lenght of 3 - 5" fletch, but it gives a lower profile so a bit less drag.
He only real advantage is the fact that the arrow nocks correctly any way you put it on.
Now, some guys shooting woodies prefer high natural turkey feathers that "SWOOSH" when shot.
As far as shield, parabolic, bannana, or other cuts, I don't think it makes a big difference. The whole idea of having feathers on the end of the shaft is to slow down the rear end so they will fly true. As long as you have enough fletching to do this, you should be good. Any more, you are slowing the shaft more than you need to.
Another issue is straight fletch, spiral fletch, or helical fletch. The less angle you have on an fletch, the faster it will fly. The more angle, or helix, on the arrow, the more it will spin, making it a tad slower, but more accurate. Kinda like rifling on a bullet. Some broadheads, when used with straight fletch can cause an arrow to drift or plane, making the arrow porpose up and down. A spinning shaft will not do this.
Purely personal choice.
Just my thoughts.