You are absolutely welcome here, and your question is an interesting one for us to ponder. Thanks for bringing it up!
However, the N-SSA has a forum of its own, and they are serious about target accuracy. Maybe post your question there also. Chances are pretty good that somebody there has considered this topic before, and may be able to give you the information you seek.
If you conduct any carefully controlled experiments, though, comparing perfectly spherical balls to out-of-round balls, I would be interested in the results.
Are your three moulds for the same sized balls? What size are they supposed to be?
Notchy Bob