The Army Builder output says:
"sW: Rending To Wound roll of 6 = Auto wound, No Armour Save. Penetration roll of 6 adds one additional D6 to the
result. (WH40k pp. 31,42)"
This is incorrect. The penetration roll only adds d3. (See page 31.)
Also, the "No Armour Save" is imprecise: it counts as AP2.
"sW: Rending To Wound roll of 6 = Auto wound, No Armour Save. Penetration roll of 6 adds one additional D6 to the
result. (WH40k pp. 31,42)"
This is incorrect. The penetration roll only adds d3. (See page 31.)
Also, the "No Armour Save" is imprecise: it counts as AP2.