Gonna echo blockcaver. I mean no offense today anyone. Let me be clear. Idc what you shoot. My passion is working a tracking dog. (I will get out of the deerstand to go track) I track 20-25 deer/bear a year. Tracked and recovered 3 in the last week. I hunt traditional now but hunted with a compound over 20 years.
All my findings are my observations, and anecdotal at best. Generally i believe there is no replacement for displacement. That said it doesnt apply to archery. There is no replacement for marginal shots in my experience. What i see is 3_4 fixed put the best "trackable" blood trails with the least amount of sacrifices. Penetrations, failures, etc. What i see in two blades, fixed or mechanicals, is vertically oriented cut esspecially in between ribs have marginal bloodtrails. Single bevels seem to come up short more times than not on blood. And the rotation is very minimal in reality. Blade orientation on entry is out of your control obviously. This is why i like 3_4 blades. I dont care if the deer goes 100_150 if i can follow the bloodtrail. I also only see problems..... People dont pay me to track there deer that paint the woods and fall in sight. I have tracked several that go a hundred plus yards with no blood then pour blood. But generally they bleed or they dont. The broadhead i recommended to my elderly father was the 3 blade cutthroats. (He loves sharpening broadheads). I really think specs rather more than brand and agree with all of those recommended above. Also i realize this was about elk, but if you are shooting whitetails, for godsake dont shoot them head down!
Good luck this season fellas