toughness Armour save Poison minus 3 arm plus 1 wound multiple shots
3.0 1.0 0.37 0.74 0.35 0.35
3.0 2.0 0.74 0.98 0.69 0.69
3.0 3.0 1.11 0.12 1.04 1.04
3.0 4.0 1.48 1.47 1.39 1.39
3.0 5.0 1.85 1.47 1.74 1.74
3.0 6.0 2.22 1.47 2.08 2.08
4.0 1.0 0.31 0.49 0.26 0.23
4.0 2.0 0.62 0.65 0.52 0.46
4.0 3.0 0.93 0.08 0.78 0.69
4.0 4.0 1.23 0.98 1.04 0.93
4.0 5.0 1.54 0.98 1.30 1.16
4.0 6.0 1.85 0.98 1.56 1.39
5.0 1.0 0.25 0.25 0.17 0.12
5.0 2.0 0.49 0.33 0.35 0.23
5.0 3.0 0.74 0.04 0.52 0.35
5.0 4.0 0.99 0.49 0.69 0.46
5.0 5.0 1.23 0.49 0.87 0.58
5.0 6.0 1.48 0.49 1.04 0.69
6.0 1.0 0.25 0.25 0.17 0.12
6.0 2.0 0.49 0.33 0.35 0.23
6.0 3.0 0.74 0.04 0.52 0.35
6.0 4.0 0.99 0.49 0.69 0.46
6.0 5.0 1.23 0.49 0.87 0.58
6.0 6.0 1.48 0.49 1.04 0.69
This was run with the same unit given different arrows and adding up to 100 points (including fractions of models). It was run against all reasonable arm saves you could see on a block. Whats interesting is the poison arrows do the most wounds per point except for the extremely high armour saves. This situation is run at long range (so including a single -1 modifier). I did not run the trueflight arrows, because their worth is hard to measure, it depends on the possible modifier you are ignoring. This bonus does not include the flaming portion of the +1 to wound arrows and assumes you are shooting at the type you have the bonus against. Do not take this math as word of law, im liable to have messed up somewhere, I'm not perfect
I was unsure how the +1 to wound arrows worked on shots that needed a 6 to wound (such as toughness 5) I ran it as if they would need a 5+ if this is not the case then the number would go down.