Icefire7890 wrote:But would each of those extra hit rolls themself be x3 since for each hit roll you make with that profile you make 3 instead?
Ie 24 total attacks as the errant since it's 8 attacks total each one causing 3 extra hits since in sweep
No, you are muddling up Attacks and Hit rolls. The key thing to look at is the wording on the Stratagem:
if that attack is made using the Sweep profile of a reaper chainsword or reaper chain-cleaver (or a Relic that replaces such a weapon), make 1 additional hit roll.
Each Attack gets an extra Hit roll. Now compare that to the wording for the Reaper:
Each time an attack is made with this weapon profile, make 3 hit rolls instead of 1.
From this you can see that an Attack is not the same as a Hit roll. An attack, may make more than one Hit Roll but each roll is not an Attack.
For the specific case of the Errant you get Number of Attacks on the Profile x (Hit rolls from the Sweep profile + Bonus for Stratagem).
4 x ( 3 + 1 ) = 16 Hit rolls