i think your basic premise is correct. i also think that in that lesser penetration the bullet is transferring more and all of its considerable energy to the target.

Underwood 200 and 220 grain hardcast. 1250 fps 694 ft. lbs , 1200 fps 700 ft. lbs

i grew up with moose. They can be anywhere from almost friendly to down right nasty. This animal was posturing very early in the video to stay away and he died because the guy did not listen. i think the deep snow had the moose on the trail and the snow mobile pressed the issue coming forward. Just one shot from that moose's hooves could have killed him. This was a no win situation.