I've never understood the physiology of shot placement and what does and does not precipitate good blood trails with bears. It seems at times like two different shots with two different broadheads that end up in the same place can end up with two different types of blood trails. And while I've certainly never hunted brown bears (although I sure would love to!!!), for black bears, I've always stuck with the same ol’, same ol’ – the Zwickey 2 blade Delta with great results.
With bears, the bottom line is, if you put that 2 or 3 blade broadhead where it needs to be, bears go down much quicker than whitetails. Take whatever setup you shoot most accurately and effectively. Wait for that broadside shot when you can get BOTH lungs and you won't have to worry about a blood trail – the bear will likely go down within sight.
Best wishes for your hunt of a lifetime! Looking forward to reading about it!