So my question is this. If you target a rank and file (RnF) model in base contact and the model fails the initiative test, do you auto hit 4 RnF models (4 is the Soul Grinders base attacks)? With the current 'step up' system I'm getting that impression. Exact wording of rule for those without the Daemon book:

Immediately before the Soul Grinder makes its Attacks, nominate one model in base contact with the Soul Grinder. That model must pass an Initiative test. If the test is passed, nothing happens. If the test is failed, all other attacks the Soul Grinder makes against that model this turn hit automatically.