Perhaps a number of trials are in order.
Give some shooters, selected or chosen at random, a few cards each with various guns, and and see what the results are.
I know we have had a look at some downwards scoring cards, and and have seen what they would score upwards scoring, but have these same shooters shot a few rounds with a springer to see how much, if any, they are disadvantaged by?
I am sure such an exercise will show a way forward.
Kind regards,
Phil