Yes a heavier arrow would work but a lot of individuals do not want to shoot heavier arrows. Myself I prefer them but a lot of archers do not like going over the 500 grain threshold. Why? I have no idea. You are right a more efficient BH, a little heavier arrow, or more draw weight would benefit greatly. But let's also address that if we watch these arrow flights from these TV Hunters I guarantee the majority of them will be horrible. Some look like a wet noodle flying through the air, some fish tail bad, and the list goes on. I will also bet the majority do not tune their bow fast the general 6 foot paper tune. I doubt they shoot bareshafts at 40 yards to check the bows tune along with fine tuning form, nock tuning each arrow, I'm sure a lot torque the bow when shooting, and this list also goes on also.And yet we see TV hunters all the time shooting an elk broadside with nothing but ribs in the way, and there's 15" of the fletching end of the arrow still hanging out of the bull. I think they could have benefitted from a heavier arrow........or a more efficient BH.........or more draw weight......or a combo of any or all three.
Archers can severely hinder their penetration just by horrible arrow flight alone whether it is an under spinned arrow to a bow that is not tuned.