Let me try, as simply as I can, to illustrate what we mean by this being impossible.
I burn in two very efficient fireplace inserts. I will burn most any size wood I can get my hands on. Rather than chip or discard small stuff, I go ahead and firewood it down to about 2" diameter, all 16" long (to fit my smaller insert). My partner uses an OWB that can handle unsplit 18" diameter, up to 30" long, with no problem. For the sake of this exercise, let's make a few assumptions:
1) Let's assume no voids in the chord of stacked wood (not realistic at all).
2) Let's assume my load is an average of 3" diameter and all 16" long.
3) Let's assume my partner's load is from our latest cleanup job, a 52" willow oak, cut in 24" long rounds.
Based on the above assumptions, my load would be 1,956 pieces of firewood and my partner's load would be 4 1/3 rounds off the trunk of the willow oak. So we have a variation in the piece count of over 1,900 pieces.
Understand?