Do you think the largest Perd with stacks on both sides was a cast-off, or?
Could that show the evolution of a ? tool. Do you think they would have
eventually been able to knock the stacks off and refine that piece?
Perds of that size and up can be correctly called "knives".
The maker may not have had a need to having it hunting shaft quality so the stacks would /could be left.
Of course it could also fall into the category of ANY worked flint that is not fantastic quality.....no telling what age & experience of the person might have that created the piece and what we see is the best he / she could achieve.
Hang in there...we know there is sure to be rain for the annual Digfest in October