Im not worried about splashing wounds over, but now i have reliable D2 wounds for all multi wound models.
83.33% chance to hit (on turn 3), then a 16.67% (then add the re-roll) chance to get a 6 on the dice with 2 tries) to do Mortal wounds. If my math is correct it will take 4 attacks to get 1 D3 mortal wound.
Talked to some of my math genius friends (went to school for math literally)
Basically it comes down to are you fighting 2+ multi wounds guys or MEQ or lower. Against MEQ its its about the same, against 2+ armor or 3+ armor with 3+ wounds the Mortal Wounds are better.
So its more situational than anything.