If you haven't already, look up the arrow lethality research done by Dr Ed Ashby. This isn't some little hobby he did with his buddy over a couple beers, but involves literally tens of thousands of archery kills on big game. The factors that go into high lethality arrows are simple, high FOC, high arrow weight, and fixed two blade broadhead - preferably with single bevel to coincide with the rotation imparted with the fletching.
Bear hides are not tough like moose or elk, and their ribs are akin to deer. Getting full pass through with the proper arrow combination is VERY doable. I'd expect it! Pass through means TWO sucking chest wounds helping collapse both lungs simultaneously, TWO blood trails, and no shaft plugging up the wound channel. That in itself cancels the extra cutting edge (and increased resistance) of a three blade.
Again, read the Ashby research. Look at how the research was conducted and how they come to the conclusions that they do. Most any bow will do. The terminal tackle, the point of the whole issue (to coin a phrase), is the best arrow you can send.