So, this topic has come up a few times in the past. Your the licensed hunter take the shot you are confident in.

For the point of discussion though. The great vessels in the neck bleed out quickly. Perhaps quicker than a heart shot as the heart is still desperately pumping to keep the blood pressure up. Which forces the blood to drain quicker. If your arrow hits the heart it's not going to be able to produce an organized contraction cycle and the pulse will either slacken, or fail. Most likely fail.

Like any shot you have to take them as they come and evaluate them in the moment. If you don't feel you can make a humane kill hold off for a better opportunity.

You know what, I think I'll go shoot by bow.