For me, it's the whole thing.. not just the overpowering of 3 live victims.. it's the getting them out of the home and into the truck, and in relation to his size, although I shouldn't make that kind of judgement on shorter people, and supposedly cleaning up after himself on at least the outside of the home, if not the inside too, which we don't know, and multiple visits to the home with drives of ? miles each way in between the back and forth 'multiple' visits, and disposing of the bodies somewhere all within a max of 12 hours.
After discussion on WS it seems unlikely that it was really 12 hours that the perp had to work within, since sunrise was at whatever time, cutting his time by at least 4 hours or more, and so realistically, he would have had to have been completed his tasks and gone before sunrise, (unless he is a complete moron, I think, but the accused has been reported rather, to be a 'genius'). And also the travelling down the roadways with 3 bodies in the middle of the night, I'm presuming Calgary has a police presence on the roads and at night, and it seems so very risky to do that..
And then combine all of that with the fact that some want to think the perp chopped up the bodies to make it easier to transport to and from the truck,.. all of these things take time.. and I would imagine that the killer would be under high stress, especially since there was one more body than expected to have to deal with and dispose of.. I'm just not getting how all of that is possible within those few short hours. And where did he take them.. would he really bring the evidence to his home? That would be really non-genius thinking.
So I'm certain it wouldn't have been a problem to overpower 3 people if they were sleeping, it's all the other things and the timelines and that he did all of that by himself without leaving any 'smoking guns' for evidence. MOO