I think we're all pretty well in agreement that shot placement and adequate power are both important to varying degrees. But I find it to be nearly impossible to quantify the power component. In my experience, energy is a rather useless metric. People use it because it's an easy metric and one printed on boxes and ballistic charts. In other words, I feel it's a lazy metric and not a very good one either. It tells me absolutely nothing important for decision-making purposes. Alas, delivering killing shots on animals is more akin to art than science. It involves science but the execution (pun intended) is more art.
For bullets and blades (arrows), diameter, mass and velocity tell me far more important things. Of the three, I'd compromise on velocity first in favor of mass and diameter. Velocity doesn't even do much until we're north of about 2400 fps. Below that, it's still more about mass & diameter. Structural integrity is another component but a fuzzy one depending on what is desired (expansion or cutting diameter vs penetration). Personally, I'd rather have all of my hunting shots be pass-throughs without exception.