RE: wild boar hunting
A quartering away shot is more important on a hog than deer even. Boars have heavy "plating" over their shoulder area they use when fighting. You need to hit them a bit farther back than deer and the quartering away angle ensures the arrow gets up into the lung/heart area. You can take them broadside but you need to know where that plating stops and/or have a good fixed blade head with plenty of KE to punch through it.