rending and tank hunter

with pask in the new imperial guard codex being popular as well as the o'vesa star both of which have tank hunter and rending, i thought i would clarify how the rerolls from tank hunter apply to rending.
You DO NOT reroll failed armour pen rolls before you roll the additional d3 for rending, you also DO NOT get to reroll the d3, it goes something like this:
1. you roll to hit as normal
2. you roll armour pen rolls as normal
3. for every six you roll you then roll an additional d3 and add the result to the 6 + the weapons strength
4. if the result is still not enough to pen the armour you discard the d3 and reroll the 6 (as well as all non-6s that you originally rolled) in hopes of getting another 6
5. if you get another six you roll another d3 and add it to the 6 + weapons strength, if this result is still not enough then there are no more rerolls allowed and you have failed to pen the vehicle.

The process works like this because the d3 is not a armour pen roll, but is an additional dice added to your overall result (Rulebook pg41) and tank hunter says you only reroll failed armour pen rolls (rulebook pg43) and since this d3 is not part of the armour pen roll you do not get to reroll it and instead may reroll the 6 in the hopes that you get another 6 and then get a better roll on your d3

I hope this clarifies things for people that did not know how it worked and indeed i wasnt sure how it worked until i looked into it deeper, and if you think im wrong let me know below and make sure you have information to back up your oppinion.

good info pat