If cause of death was Exsanguination, (bleed out), that could be caused from stab wounds, internal bleeding from damage (think broken bone that pierces something important), severe head trauma. All four might have died of Exsanguination. All four might have had one or more fatal stab wounds. All four may not have died of only stab wounds and still died of exsanguination.
I think about things like that because my friend died of "asphyxiation". Sadly, it was not just a pillow over her face but more than one type of asphyxiation to the point the autopsy was the only way to know the story. The autopsy still said asphyxiation, not asphyxiation by xxxxxx and yyyyy and zzzzzz. The autopsy report can be kind of clinical in an almost two dimensional way that doesn't explain the reality, IMO.
Now, maybe the autopsies specify exsanguination by laceration of xxxxxx for all four, which makes it seem like they all died exactly the same way. And maybe the reality of what you see in the funeral parlor doesn't match the emotionless words on a page. I know it didn't for me. JMO.