I guess you didn't get many practice shots with the pecan shell whistler being it is so thin.
Funny enough, I let my Son have a go shooting the whistling arrows, 'cos it's such a laugh.
I'd made 2 Walnut and one Pecan...
He grouped the 2 walnut so close he smashed the shells on both of 'em
Fortunately they are quick to make and the Pecan being skinny fit into a quiver easier.
However, they aren't so good at stopping a Pecan Pie which is rolling at full speed to escape... ironically the Walnuts may be better for pie shooting.
Broadheads are certainly no good, they go stright through, but if you are lucky enough to get a kill, the pie may be ready sliced for eating
Del
PS. Once glued on the shaft, they are pretty robust for normal use, but they still bury into the foam boss and make a mess of it when shot from anything over 35#...