Hey guys! I've never taken an animal with a Traditional bow, But our small group of archery hunters have taken 34 elk in the last 16 years, and God knows how many deer....the deer are like rabbits to us out here in Oregon. I can offer opinions on just about every kind of shot senario imaginable, and the two hole theory of a pass though is good if the shot is low or angled down like from a tree stand. Most of our group are stalkers, so we are usually dealling with either up hill, down hill, or on the flat shots. Pass though shots are common with compound bows IF, and i say "IF" the shot placement and angle is right.The angle of your arrow is the most important part. Think of shooting a plastic barrel full of water....The closer you shoot to the bottom of the barrel, the more water is going to leak out....I know this doesn't take into account the vitals, but when you get a hole in the botton of a critter, they leak more....PERIOD. I've seen many text book high lung broadside pass thoughs on level ground that never resulted in a harvest due to no blood trail at all....Take that same shot and lower it 4" on a deer, or 8" on an elk, and it looks like someone used a spray gun with red paint though the woods, pass though or not.....So my experience is this: From a tree stand or a steep down hill shot: Pass though is best. Up hill shots are nice!. You get a hole in the bottom, pass through or not.... When sooting on level ground hitting high is bad, pass though or not.A mid body shot i would almost prefer that arrow to stay in the animal. 9 times out of ten they break that arrow off and leak just as good as a pass through. I like a quartering away shot the best. a low shot for the heart ends in the arrow usually through the liver & lung , and into the inside of the rib cage or shoulder on the other side. If you get the heart...10 to twenty yards and they are down. Even without a pass through they don't run far at all.
Bottom line is shot placement, and angle of entry. Poke a hole in the bottom.....They leak more.....I'd rather shoot a lower heart shot and miss completely than get a high double lung pass through.....Been there.... done that....lost some nice critters that way..... Shoot for the heart guys and you'll harvest more critters.