No doubt the .375 H&H is an excellent bear round, but I think there’s a fundamental difference between the kind of weapon I’d take if deliberately setting out to hunt bear (in which case the .375 would be at or very near the top of the list) and what I’d take for close range defense if merely packing/camping/hiking in bear country, or supervising a group of campers/hikers. IMHO, I think my first choice for the latter would probably be an AR platform carbine in .50 Beowulf, with my second choice a quick lever gun in .45-70, .450 Marlin or .444 Marlin, with a .480 Ruger or .454 Casull as a last ditch back up.
The 45-70 and 444 Marlin are in the top 10 of the list. 458 Win. Mag #1, 375 H&H #2, 338 Win Mag. #3. 30-06 w/250 gr. rnd nose, #4, 45-70 #5.
In the hands of a competent guide, there is nothing more effective that a 375 H&H. A 350 gr. RN delivers 5800 foot pounds of energy out to 25 yards. No Brownie on Earth could stand up to a solid, well placed hit from one of these.
I would pick it over a 458 because it has less recoil and the shooter recovers much quicker for a followup shot. (I have had actual experience stopping a charge.)
Indians down Ft Yukon killed a polar bear sow 3 years back with an AR, 55 grain .556
All the bear we got this Spring was with 6.8 stag 15. They didn't run 30 yards, collapsed.
I have a couple 460 S&W's, way more than a 44.