I do too. E has to be a factor to consider here, because unless he was completely plastered out of his wits, there's no way BK could have murdered X, with her crying all the while, and somebody talking to her, without E waking up and reacting somehow. And we know X was awake during the whole event, so how could BK murder E without X either fighting him, shouting, or fleeing, especially if she wasn't cornered in the room, but right by the door. DM didn't report hearing any of this kind of sound (unless she did but it wasn't included in the PCA).
Instead, DM reports hearing crying, twice, coming from X's room. I know it's contentious whether or not that is blood dripping down the side of the house, but its placement would be consistent with a body bleeding against the wall of that room, the wall nearest where the camera captured a loud thud at 4:17. I think that was E and BK. I do think other posters' idea about the order the murder charges were listed could be order of death (maybe, maybe not), but maybe X was stabbed before E, injured, then E was killed, and finally, BK came back to X to "help" her, and he finished the job right before DM saw him leave. It's the only way I can put all the details together with what I know so far, which isn't much...