So, my question is, is there anything about that semi-skinner style blade shape that is measurably better than any of the other blade styles below for looking after a downed animal from start to finish?
Sort of. The semi-skinner is a generalist applicable to a lot of tasks rather than a specialist that is ideal for one and sucks for the rest. Those bottom 2 pictures you posted .. I like those. Pretty sure I could get along with them nicely. What we should do, IMHO at least, is get a general purpose design created from good steel with a grip that fits our hand, sharpen the crap out of it, then get busy trying to wear it out. In other words, I think we should focus on developing our skills with a generalist knife instead of trying to compensate for the skills we don't have by throwing money into a special purpose knife for it.
I use all kinds of different shapes. Figure out how to grab whatever knife is handy and use it in a way that plays to its strengths and away from its weaknesses. The only thing y' gotta really do so far as selection is avoid the "stupid knives" .. movie props and the like .. that have no strengths, they're just knife-maker artwork, not practical / functional.
