Like anything, it takes the right equipment and the desire to practice, practice, practice. I've guided many a rifle hunter on whitetail in south Texas and have had to follow/track many a wounded deer. Heck, I'm been guilty of making bad shots, rifle and bow, that I am not proud of, way more than I'd care to admit in public.
There's a saying. "Train like you hunt, hunt like you train."
Shooting on a bench with bags is great. Shooting your bow at 20 yards at the indoor range standing up is nice too.
Any weapon, in the hands of the properly trained person, can be deadly effective. In the wrong hands, that same weapon can be worthless and ineffective.
If someone is willing to research and learn about their equipment and decide on how they need it to perform on a certain species of animal, then they increase their odds of making a quick, ethical kill.
My daughter was pulling 52 lbs with her bow on her trip to Namibia. We are firm believers in the GrizzlyStik arrow system. Heavy arrow, heavy two bladed head, with a High front of center. Her arrows weigh 580 grains and that includes the 200 grain single bevel broadhead. Many will already scoff and gasp at that. I don't care. She shot a Kudu bull. Complete pass through lung shot at 20 yards. It ran 40 yards. She shot an Impala, quartering too her, at 20 yards. She hit it in the front shoulder, going through bone. Complete pass through. Impala jumped over the water trough and hit the ground dead. The warthog, hit it a bit high at 27 yards I think, and another complete pass through. It ran about 150 yards and died. Her wildebeest. Mix up with the PH, he was ranging one and she shot another. The one she shot was quartering away slightly at 25 yards. Arrow hit the front shoulder bone, got about 10-12" of penetration. Arrow broke the right front leg. Animal ran on three legs and made it about 80 yards. None of these animals required a follow up shot.
We could start a thread on "who has the worst story on someone wounding an animal, rifle or bow" and there would be a hundred posts within a week, with reports equally on both rifle and bow.
We could start one on heavy versus light, again, rifle bullet or arrow, and the discussion would get heated and have numerous "scientific studies have proven ?" comments to further the argument.
And for some reason, when it comes to arrows, arrow weight, broadheads, arrow speed, etc., things get ugly fast. While we can all agree that it makes no sense to shoot a cape buffalo with a 150 grain hollow point traveling at 3500 fps, that same argument is not considered the norm when it comes to arrows and animals.
I don't want to start a heated argument over heavy and slow arrows, with a high FOC vs lighter, faster arrows with a lower FOC. I've learned to just let those be. People will decide for themselves and that's fine by me. You shoot what you want, I'll shoot what I want, and we're both happy.
Side note, on the topic. My daughter is in College Station and recently took both her bows back to school with her. She went to a bow shop there this week for the first time and had them do some work on her bow. She went by herself and I had a talk with her before she went. I told her to expect them to ignore you at first but once they ask you what you need, tell them what you need. I told her, you're a young woman, with a bow, and they are going to assume you are pretty much ignorant and have never hunted with this toy of yours. I told her once they start to help her and they see her arrows, expect the "what the hell?" comments to follow. "A girl shooting a bow and her arrows are bricks! Are you f'n kidding me? Who told her to shoot this stuff?"
Guess what? That's exactly what happened. No one would help her for several minutes, they just looked at her as she held her gear waiting patiently. When the first guy finally asked her what she needed, she began talking to him. He picked up one of her arrows and was shocked by it's weight. Then they all gathered around and the discussion began about why a girl is shooting a 580 grain arrow. I told her to expect that and to not fold to their way of thinking and to not try and change their way of thinking. Just tell them it's the system you believe in and ask if they are going to help you tune your bow are not? One of them said it was way to much arrow for deer and that's when she said she has them for plains game in Africa. Now that's when I wish I had been a fly on the wall. She said they really about fell over then and they started asking about her animals she had taken. I think they came to respect her at this point and showed her the proper attention every customer deserves. They helped her with her bow and made some tweaks to it and hopefully she made some new friends. They advised her of a local, outdoors archery range to which she has already paid her yearly membership dues and she hopes to start shooting there this week. It sounds like in the end, they where very helpful and I'm hoping she has found a place to go and have her bows worked on while also making some new friends in the process.
But I get the same responses when I go in my bow shop. The guys that work there think I'm crazy for shooting such heavy arrows and other customers ask me all the time "what are you expecting to shoot with those?" My arrows weigh in at 665 grains and I wouldn't have them any other way.