Placement - the head has to get into the vitals to cut, how big of head doesn't help with poor shot placements, and not waiting for the right angle.
JMHO, I see a number of hunters locally using the wide-cut heads in lieu of spending a few extra hours on the range tuning their shooting form.
With your Excaliber, many of mechanical broadheads in the 2 inch range will open with one or both blades on the shot. You would need broadheads specifically for the crossbow.
